IDocumentInspector implementation in C# causing Word to hang

[greba]

I created a new Add-in using C# that implements the IDocumentInspector
interface. When the add-in is installed (and some registry settings
are added) will cause a new Document Inspector to show up in Word
2007's Document Inspector window. If I run my inspector, and then
close down Word it will appear to close but WinWord.exe will still be
running as viewable from the Task Manager. If I don't run my
inspector, and then close down Word then WinWord.exe will not be
running as viewable from the Task Manager.

I'm using http://msdn2.microsoft.com/en-us/library/aa338203.aspx as a
basis to accomplish this.

Here are the steps I use to reproduce:
Create a new C# shared add-in for Word
Implement IDocumentInspector interface (I set the status to
Microsoft.Office.Core.MsoDocInspectorStatus.msoDocInspectorStatusDocOk,
and the out strings to "")
Build/Install.
Copy the GUID of the add-in.

Using regedit create a new registry key under HKLM\SOFTWARE\Microsoft
\Office\12.0\Word\Document Inspectors
Create a new string value with name CLSID and value of the GUID you
copied.
Create a new DWORD value with name Selected and value 1.

Start Word and run newly created inspector. Open Task Manager and see
WinWord.exe still running.

Has anyone been able to create a document inspector for office 2007?

Thanks