Fixed bug causing clicks between documents and toolpanes not to register.

Filtration/App.xaml.cs

@@ -25,6 +25,8 @@ namespace Filtration
 
         private void Application_Startup(object sender, StartupEventArgs e)
         {
+            DispatcherUnhandledException += OnDispatcherUnhandledException;
+
             _container = new WindsorContainer();
 
             var propInjector = _container.Kernel.ComponentModelBuilder
@@ -61,7 +63,6 @@ namespace Filtration
             Mapper.CreateMap<IThemeViewModel, Theme>();
 
             Mapper.AssertConfigurationIsValid();
-            DispatcherUnhandledException += OnDispatcherUnhandledException;
 
             var mainWindow = _container.Resolve<IMainWindow>();
             mainWindow.Show();

Filtration/NLog.config

@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-      xsi:schemaLocation="http://www.nlog-project.org/schemas/NLog.xsd NLog.xsd"
       autoReload="true"
       throwExceptions="false"
       internalLogLevel="Off" internalLogFile="c:\temp\nlog-internal.log" >

Filtration/ViewModels/AvalonDockWorkspaceViewModel.cs

@@ -63,6 +63,8 @@ namespace Filtration.ViewModels
             get { return _activeDocument; }
             set
             {
+                if (value == _activeDocument) return;
+
                 _activeDocument = value;
                 RaisePropertyChanged();
 
@@ -105,6 +107,7 @@ namespace Filtration.ViewModels
         }
 
         private List<IToolViewModel> _tools;
+        private FiltrationViewModelBase _activeContent;
 
         public IEnumerable<IToolViewModel> Tools
         {