Unity Editor Throwing

Reported:

I'm getting errors looking at the InspectorPanel in In Scene Inspector during edit time:

NullReferenceException: Object reference not set to an instance of an object
InSceneInspector.InSceneInspectorEditor.set_DefaultComponentIndex (Int32 value)
InSceneInspector.InSceneInspectorEditor.OnInspectorGUI ()
UnityEditor.InspectorWindow.DrawEditor (UnityEditor.Editor editor, Int32 editorIndex, Boolean rebuildOptimizedGUIBlock, System.Boolean& showImportedObjectBarNext, UnityEngine.Rect& importedObjectBarRect) (at C:/buildslave/unity/build/Editor/Mono/Inspector/InspectorWindow.cs:1235)
UnityEditor.DockArea:OnGUI()

Also, the use of In Scene Inspector seems pretty sluggish at runtime. I'm having to double and triple click a game object or checkbox and even then it doesn't always select it...