diff --git a/src/AddIns/DisplayBindings/FormsDesigner/Project/Src/Gui/CustomComponentsSideTab.cs b/src/AddIns/DisplayBindings/FormsDesigner/Project/Src/Gui/CustomComponentsSideTab.cs
index 3de5106cc5..2ab64c7c44 100644
--- a/src/AddIns/DisplayBindings/FormsDesigner/Project/Src/Gui/CustomComponentsSideTab.cs
+++ b/src/AddIns/DisplayBindings/FormsDesigner/Project/Src/Gui/CustomComponentsSideTab.cs
@@ -21,16 +21,29 @@ using ICSharpCode.SharpDevelop.Widgets.SideBar;
 
 namespace ICSharpCode.FormsDesigner.Gui
 {
-	public class CustomComponentsSideTab : SideTabDesigner
+	public class CustomComponentsSideTab : SideTabDesigner, IDisposable
 	{
+		bool disposed;
+		
 		///<summary>Load an assembly's controls</summary>
 		public CustomComponentsSideTab(SideBarControl sideTab, string name, IToolboxService toolboxService)
 			: base(sideTab, name, toolboxService)
 		{
 			this.DisplayName = StringParser.Parse(this.Name);
 			ScanProjectAssemblies();
-			ProjectService.EndBuild       += RescanProjectAssemblies;
-			ProjectService.SolutionLoaded += RescanProjectAssemblies;
+			ProjectService.EndBuild         += RescanProjectAssemblies;
+			ProjectService.SolutionLoaded   += RescanProjectAssemblies;
+			ProjectService.ProjectItemAdded += ProjectItemAdded;
+		}
+		
+		public void Dispose()
+		{
+			if (!disposed) {
+				disposed = true;
+				ProjectService.EndBuild         -= RescanProjectAssemblies;
+				ProjectService.SolutionLoaded   -= RescanProjectAssemblies;
+				ProjectService.ProjectItemAdded -= ProjectItemAdded;
+			}
 		}
 		
 		void RescanProjectAssemblies(object sender, EventArgs e)
@@ -41,6 +54,13 @@ namespace ICSharpCode.FormsDesigner.Gui
 			SharpDevelopSideBar.SideBar.Refresh();
 		}
 		
+		void ProjectItemAdded(object sender, ProjectItemEventArgs e)
+		{
+			if (e.ProjectItem is ReferenceProjectItem) {
+				RescanProjectAssemblies(sender, e);
+			}
+		}
+		
 		void ScanProjectAssemblies()
 		{
 			// custom user controls don't need custom images
diff --git a/src/AddIns/DisplayBindings/FormsDesigner/Project/Src/ToolboxProvider.cs b/src/AddIns/DisplayBindings/FormsDesigner/Project/Src/ToolboxProvider.cs
index 7282fa0712..42385ccae2 100644
--- a/src/AddIns/DisplayBindings/FormsDesigner/Project/Src/ToolboxProvider.cs
+++ b/src/AddIns/DisplayBindings/FormsDesigner/Project/Src/ToolboxProvider.cs
@@ -26,8 +26,10 @@ namespace ICSharpCode.FormsDesigner
 		static ICSharpCode.FormsDesigner.Services.ToolboxService toolboxService = null;
 		public static List<SideTab> SideTabs = new List<SideTab>();
 		
-		static ComponentLibraryLoader componentLibraryLoader = new ComponentLibraryLoader();
+		static CustomComponentsSideTab customTab;
 		
+		static ComponentLibraryLoader componentLibraryLoader = new ComponentLibraryLoader();
+
 		public static ComponentLibraryLoader ComponentLibraryLoader {
 			get {
 				return componentLibraryLoader;
@@ -90,7 +92,7 @@ namespace ICSharpCode.FormsDesigner
 				tab.ItemsExchanged -= SideTabItemsExchanged;
 				if (SharpDevelopSideBar.SideBar.Tabs.Contains(tab)) {
 					SharpDevelopSideBar.SideBar.Tabs.Remove(tab);
-					reInsertTabs = true;;
+					reInsertTabs = true;
 				}
 			}
 			reInsertTabs &= doInsert;
@@ -108,7 +110,10 @@ namespace ICSharpCode.FormsDesigner
 					}
 				}
 			}
-			SideTabDesigner customTab = new CustomComponentsSideTab(SharpDevelopSideBar.SideBar, ResourceService.GetString("ICSharpCode.SharpDevelop.FormDesigner.ToolboxProvider.CustomComponents"), toolboxService);
+			if (customTab != null) {
+				customTab.Dispose();
+			}
+			customTab = new CustomComponentsSideTab(SharpDevelopSideBar.SideBar, ResourceService.GetString("ICSharpCode.SharpDevelop.FormDesigner.ToolboxProvider.CustomComponents"), toolboxService);
 			customTab.ItemRemoved += SideTabItemRemoved;
 			customTab.ItemsExchanged += SideTabItemsExchanged;
 			SideTabs.Add(customTab);