diff --git a/src/Umbraco.Core/Cache/CacheKeys.cs b/src/Umbraco.Core/Cache/CacheKeys.cs
index 5b31a4f315..1c89d7662f 100644
--- a/src/Umbraco.Core/Cache/CacheKeys.cs
+++ b/src/Umbraco.Core/Cache/CacheKeys.cs
@@ -6,6 +6,9 @@ namespace Umbraco.Core.Cache
     /// </summary>
     public static class CacheKeys
     {
+        public const string ApplicationTreeCacheKey = "ApplicationTreeCache";
+        public const string ApplicationsCacheKey = "ApplicationCache";
+
         public const string UserTypeCacheKey = "UserTypeCache";
 
         public const string ContentItemCacheKey = "contentItem";
diff --git a/src/Umbraco.Web/Cache/ApplicationCacheRefresher.cs b/src/Umbraco.Web/Cache/ApplicationCacheRefresher.cs
new file mode 100644
index 0000000000..a9e52fbb2f
--- /dev/null
+++ b/src/Umbraco.Web/Cache/ApplicationCacheRefresher.cs
@@ -0,0 +1,43 @@
+using System;
+using Umbraco.Core;
+using Umbraco.Core.Cache;
+
+namespace Umbraco.Web.Cache
+{
+    /// <summary>
+    /// Handles Application cache invalidation/refreshing
+    /// </summary>
+    public sealed class ApplicationCacheRefresher : CacheRefresherBase<ApplicationCacheRefresher>
+    {
+        protected override ApplicationCacheRefresher Instance
+        {
+            get { return this; }
+        }
+
+        public override Guid UniqueIdentifier
+        {
+            get { return Guid.Parse(DistributedCache.ApplicationCacheRefresherId); }
+        }
+
+        public override string Name
+        {
+            get { return "Applications cache refresher"; }
+        }
+
+        public override void RefreshAll()
+        {
+            ApplicationContext.Current.ApplicationCache.ClearCacheItem(CacheKeys.ApplicationsCacheKey);
+        }
+
+        public override void Refresh(int id)
+        {
+            Remove(id);
+        }
+
+        public override void Remove(int id)
+        {
+            ApplicationContext.Current.ApplicationCache.ClearCacheItem(CacheKeys.ApplicationsCacheKey);
+        }
+
+    }
+}
\ No newline at end of file
diff --git a/src/Umbraco.Web/Cache/CacheRefresherEventHandler.cs b/src/Umbraco.Web/Cache/CacheRefresherEventHandler.cs
index 6176446088..025748cf13 100644
--- a/src/Umbraco.Web/Cache/CacheRefresherEventHandler.cs
+++ b/src/Umbraco.Web/Cache/CacheRefresherEventHandler.cs
@@ -21,7 +21,16 @@ namespace Umbraco.Web.Cache
     public class CacheRefresherEventHandler : ApplicationEventHandler
     {
         protected override void ApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
-        {          
+        {   
+            //bind to application tree events
+            ApplicationTree.Deleted += ApplicationTreeDeleted;
+            ApplicationTree.Updated += ApplicationTreeUpdated;
+            ApplicationTree.New += ApplicationTreeNew;
+
+            //bind to application events
+            Application.Deleted += ApplicationDeleted;
+            Application.New += ApplicationNew;
+
             //bind to user type events
             UserType.Deleted += UserTypeDeleted;
             UserType.New += UserTypeNew;
@@ -116,6 +125,35 @@ namespace Umbraco.Web.Cache
             MediaService.Trashing += MediaServiceTrashing;
         }
 
+        #region ApplicationTree event handlers
+        static void ApplicationTreeNew(ApplicationTree sender, System.EventArgs e)
+        {
+            DistributedCache.Instance.RefreshAllApplicationTreeCache();
+        }
+
+        static void ApplicationTreeUpdated(ApplicationTree sender, System.EventArgs e)
+        {
+            DistributedCache.Instance.RefreshAllApplicationTreeCache();
+        }
+
+        static void ApplicationTreeDeleted(ApplicationTree sender, System.EventArgs e)
+        {
+            DistributedCache.Instance.RefreshAllApplicationTreeCache();
+        } 
+        #endregion
+
+        #region Application event handlers
+        static void ApplicationNew(Application sender, System.EventArgs e)
+        {
+            DistributedCache.Instance.RefreshAllApplicationCache();
+        }
+
+        static void ApplicationDeleted(Application sender, System.EventArgs e)
+        {
+            DistributedCache.Instance.RefreshAllApplicationCache();
+        } 
+        #endregion
+
         #region UserType event handlers
         static void UserTypeUpdated(UserType sender, System.EventArgs e)
         {
diff --git a/src/Umbraco.Web/Cache/DistributedCache.cs b/src/Umbraco.Web/Cache/DistributedCache.cs
index ffc43c1a73..a0ce50d4c7 100644
--- a/src/Umbraco.Web/Cache/DistributedCache.cs
+++ b/src/Umbraco.Web/Cache/DistributedCache.cs
@@ -35,6 +35,8 @@ namespace Umbraco.Web.Cache
 
         #region Public constants/Ids
 
+        public const string ApplicationTreeCacheRefresherId = "0AC6C028-9860-4EA4-958D-14D39F45886E";
+        public const string ApplicationCacheRefresherId = "B15F34A1-BC1D-4F8B-8369-3222728AB4C8";
         public const string TemplateRefresherId = "DD12B6A0-14B9-46e8-8800-C154F74047C8";
         public const string PageCacheRefresherId = "27AB3022-3DFA-47b6-9119-5945BC88FD66";
         public const string MemberCacheRefresherId = "E285DF34-ACDC-4226-AE32-C0CB5CF388DA";
diff --git a/src/Umbraco.Web/Cache/DistributedCacheExtensions.cs b/src/Umbraco.Web/Cache/DistributedCacheExtensions.cs
index 48f8bf7bdd..f9ae3b8d6e 100644
--- a/src/Umbraco.Web/Cache/DistributedCacheExtensions.cs
+++ b/src/Umbraco.Web/Cache/DistributedCacheExtensions.cs
@@ -13,6 +13,20 @@ namespace Umbraco.Web.Cache
     /// </summary>
     internal static class DistributedCacheExtensions
     {
+        #region Application tree cache
+        public static void RefreshAllApplicationTreeCache(this DistributedCache dc)
+        {
+            dc.RefreshAll(new Guid(DistributedCache.ApplicationTreeCacheRefresherId));
+        }
+        #endregion
+
+        #region Application cache
+        public static void RefreshAllApplicationCache(this DistributedCache dc)
+        {
+            dc.RefreshAll(new Guid(DistributedCache.ApplicationCacheRefresherId));
+        }
+        #endregion
+
         #region User type cache
         public static void RemoveUserTypeCache(this DistributedCache dc, int userTypeId)
         {
diff --git a/src/Umbraco.Web/Cache/UserTypeCacheRefresher.cs b/src/Umbraco.Web/Cache/UserTypeCacheRefresher.cs
new file mode 100644
index 0000000000..d4ec8a0d60
--- /dev/null
+++ b/src/Umbraco.Web/Cache/UserTypeCacheRefresher.cs
@@ -0,0 +1,43 @@
+using System;
+using Umbraco.Core;
+using Umbraco.Core.Cache;
+
+namespace Umbraco.Web.Cache
+{
+    /// <summary>
+    /// Handles User type cache invalidation/refreshing
+    /// </summary>
+    public sealed class UserTypeCacheRefresher : CacheRefresherBase<UserTypeCacheRefresher>
+    {
+        protected override UserTypeCacheRefresher Instance
+        {
+            get { return this; }
+        }
+
+        public override Guid UniqueIdentifier
+        {
+            get { return Guid.Parse(DistributedCache.UserTypeCacheRefresherId); }
+        }
+
+        public override string Name
+        {
+            get { return "User type cache refresher"; }
+        }
+
+        public override void RefreshAll()
+        {
+            ApplicationContext.Current.ApplicationCache.ClearCacheByKeySearch(CacheKeys.UserTypeCacheKey);
+        }
+
+        public override void Refresh(int id)
+        {
+            Remove(id);
+        }
+
+        public override void Remove(int id)
+        {
+            ApplicationContext.Current.ApplicationCache.ClearCacheByKeySearch(CacheKeys.UserTypeCacheKey);
+        }
+
+    }
+}
\ No newline at end of file
diff --git a/src/Umbraco.Web/Umbraco.Web.csproj b/src/Umbraco.Web/Umbraco.Web.csproj
index 4cf8f78146..39f1b28bb7 100644
--- a/src/Umbraco.Web/Umbraco.Web.csproj
+++ b/src/Umbraco.Web/Umbraco.Web.csproj
@@ -263,6 +263,8 @@
     </Compile>
     <Compile Include="ApplicationContextExtensions.cs" />
     <Compile Include="CacheHelperExtensions.cs" />
+    <Compile Include="Cache\ApplicationCacheRefresher.cs" />
+    <Compile Include="Cache\ApplicationTreeCacheRefresher.cs" />
     <Compile Include="Cache\ContentTypeCacheRefresher.cs" />
     <Compile Include="Cache\DataTypeCacheRefresher.cs" />
     <Compile Include="Cache\DictionaryCacheRefresher.cs" />
diff --git a/src/umbraco.businesslogic/Application.cs b/src/umbraco.businesslogic/Application.cs
index 034f302895..efa7131196 100644
--- a/src/umbraco.businesslogic/Application.cs
+++ b/src/umbraco.businesslogic/Application.cs
@@ -6,6 +6,8 @@ using System.Linq;
 using System.Web;
 using System.Xml.Linq;
 using Umbraco.Core;
+using Umbraco.Core.Cache;
+using Umbraco.Core.Events;
 using Umbraco.Core.IO;
 using Umbraco.Core.Logging;
 using umbraco.DataLayer;
@@ -21,7 +23,6 @@ namespace umbraco.BusinessLogic
     {
         private static ISqlHelper _sqlHelper;
 
-        private const string CacheKey = "ApplicationCache";
         internal const string AppConfigFileName = "applications.config";
         private static string _appConfig;
         private static readonly object Locker = new object();
@@ -45,8 +46,6 @@ namespace umbraco.BusinessLogic
             set { _appConfig = value; }
         }
 
-        //private static List<Application> _testApps; 
-
         /// <summary>
         /// The cache storage for all applications
         /// </summary>
@@ -55,7 +54,7 @@ namespace umbraco.BusinessLogic
             get
             {
                 return ApplicationContext.Current.ApplicationCache.GetCacheItem(
-                    CacheKey,
+                    CacheKeys.ApplicationsCacheKey,
                     () =>
                         {
                             ////used for unit tests
@@ -98,15 +97,6 @@ namespace umbraco.BusinessLogic
             }                   
         }
 
-        ///// <summary>
-        ///// THIS IS USED ONLY FOR UNIT TESTS!
-        ///// </summary>
-        ///// <param name="testApps"></param>
-        //internal static void SetTestApps(List<Application> testApps)
-        //{
-        //    _testApps = testApps;
-        //}
-
         /// <summary>
         /// Gets the SQL helper.
         /// </summary>
@@ -144,8 +134,6 @@ namespace umbraco.BusinessLogic
             }
         }
 
-        
-
         /// <summary>
         /// Initializes a new instance of the <see cref="Application"/> class.
         /// </summary>
@@ -237,6 +225,9 @@ namespace umbraco.BusinessLogic
                         new XAttribute("icon", icon),
                         new XAttribute("sortOrder", sortOrder)));
                 }, true);
+
+                //raise event
+                OnNew(new Application(name, alias, icon, sortOrder), new EventArgs());
             }
         }
 
@@ -269,6 +260,9 @@ namespace umbraco.BusinessLogic
             {
                 doc.Root.Elements("add").Where(x => x.Attribute("alias") != null && x.Attribute("alias").Value == this.alias).Remove();
             }, true);
+
+            //raise event
+            OnDeleted(this, new EventArgs());
         }
 
         /// <summary>
@@ -308,11 +302,30 @@ namespace umbraco.BusinessLogic
 
                         doc.Save(AppConfigFilePath);
 
-                        //remove the cache so it gets re-read
-                        ApplicationContext.Current.ApplicationCache.ClearCacheItem(CacheKey);
+                        //remove the cache so it gets re-read ... SD: I'm leaving this here even though it
+                        // is taken care of by events as well, I think unit tests may rely on it being cleared here.
+                        ApplicationContext.Current.ApplicationCache.ClearCacheItem(CacheKeys.ApplicationsCacheKey);
                     }
                 }
             }
         }
+
+        internal static event TypedEventHandler<Application, EventArgs> Deleted;
+        private static void OnDeleted(Application app, EventArgs args)
+        {
+            if (Deleted != null)
+            {
+                Deleted(app, args);
+            }
+        }
+
+        internal static event TypedEventHandler<Application, EventArgs> New;
+        private static void OnNew(Application app, EventArgs args)
+        {
+            if (New != null)
+            {
+                New(app, args);
+            }
+        }
     }
 }
diff --git a/src/umbraco.businesslogic/ApplicationTree.cs b/src/umbraco.businesslogic/ApplicationTree.cs
index 27c7a2d04f..968b3b86cb 100644
--- a/src/umbraco.businesslogic/ApplicationTree.cs
+++ b/src/umbraco.businesslogic/ApplicationTree.cs
@@ -5,6 +5,8 @@ using System.Linq;
 using System.Web;
 using System.Xml.Linq;
 using Umbraco.Core;
+using Umbraco.Core.Cache;
+using Umbraco.Core.Events;
 using Umbraco.Core.IO;
 using umbraco.DataLayer;
 
@@ -18,7 +20,6 @@ namespace umbraco.BusinessLogic
     public class ApplicationTree
     {
 
-        private const string CacheKey = "ApplicationTreeCache";
         internal const string TreeConfigFileName = "trees.config";
         private static string _treeConfig;
         private static readonly object Locker = new object();
@@ -50,7 +51,7 @@ namespace umbraco.BusinessLogic
             get
             {
                 return ApplicationContext.Current.ApplicationCache.GetCacheItem(
-                    CacheKey,
+                    CacheKeys.ApplicationTreeCacheKey,
                     () =>
                         {
                             var list = new List<ApplicationTree>();
@@ -244,6 +245,8 @@ namespace umbraco.BusinessLogic
                     new XAttribute("action", string.IsNullOrEmpty(action) ? "" : action)));
                 }
             }, true);
+
+            OnNew(new ApplicationTree(silent, initialize, sortOrder, applicationAlias, alias, title, iconClosed, iconOpened, assemblyName, type, action), new EventArgs());
         }
 
         /// <summary>
@@ -274,6 +277,7 @@ namespace umbraco.BusinessLogic
 
             }, true);
 
+            OnUpdated(this, new EventArgs());
         }
 
         /// <summary>
@@ -289,6 +293,8 @@ namespace umbraco.BusinessLogic
                 doc.Root.Elements("add").Where(x => x.Attribute("application") != null && x.Attribute("application").Value == this.ApplicationAlias &&
                 x.Attribute("alias") != null && x.Attribute("alias").Value == this.Alias).Remove();
             }, true);
+
+            OnDeleted(this, new EventArgs());
         }
 
 
@@ -359,11 +365,39 @@ namespace umbraco.BusinessLogic
 
                         doc.Save(TreeConfigFilePath);
 
-                        //remove the cache now that it has changed
-                        ApplicationContext.Current.ApplicationCache.ClearCacheItem(CacheKey);
+                        //remove the cache now that it has changed  SD: I'm leaving this here even though it
+                        // is taken care of by events as well, I think unit tests may rely on it being cleared here.
+                        ApplicationContext.Current.ApplicationCache.ClearCacheItem(CacheKeys.ApplicationTreeCacheKey);
                     }
                 }
             }
         }
+
+        internal static event TypedEventHandler<ApplicationTree, EventArgs> Deleted;
+        private static void OnDeleted(ApplicationTree app, EventArgs args)
+        {
+            if (Deleted != null)
+            {
+                Deleted(app, args);
+            }
+        }
+
+        internal static event TypedEventHandler<ApplicationTree, EventArgs> New;
+        private static void OnNew(ApplicationTree app, EventArgs args)
+        {
+            if (New != null)
+            {
+                New(app, args);
+            }
+        }
+
+        internal static event TypedEventHandler<ApplicationTree, EventArgs> Updated;
+        private static void OnUpdated(ApplicationTree app, EventArgs args)
+        {
+            if (Updated != null)
+            {
+                Updated(app, args);
+            }
+        }
     }
 }
diff --git a/src/umbraco.cms/businesslogic/web/StyleSheet.cs b/src/umbraco.cms/businesslogic/web/StyleSheet.cs
index c73b3a337f..d9de01dcb5 100644
--- a/src/umbraco.cms/businesslogic/web/StyleSheet.cs
+++ b/src/umbraco.cms/businesslogic/web/StyleSheet.cs
@@ -238,9 +238,7 @@ namespace umbraco.cms.businesslogic.web
 
             return retval;
         }
-
-
-
+        
         public StylesheetProperty AddProperty(string Alias, BusinessLogic.User u)
         {
             return StylesheetProperty.MakeNew(Alias, this, u);
@@ -254,8 +252,10 @@ namespace umbraco.cms.businesslogic.web
             if (!e.Cancel)
             {
                 File.Delete(IOHelper.MapPath(String.Format("{0}/{1}.css", SystemDirectories.Css, this.Text)));
-                foreach (StylesheetProperty p in this.Properties)
+                foreach (var p in Properties.Where(p => p != null))
+                {
                     p.delete();
+                }
                 SqlHelper.ExecuteNonQuery("delete from cmsStylesheet where nodeId = @nodeId", SqlHelper.CreateParameter("@nodeId", this.Id));
                 base.delete();