Word 2000 offers to install help when I close it after I register my addin

I'm getting an odd problem with a word addin dll I've written. Whenever I close word I get a message saying word can't display help because it's not installed and asking if I want to install it. If I unregister the dll the message no longer appears. This only happens in word 2000, (word 2003 is fine) and only when the dll is registered. I've tried it with vanilla, SR1a, SP2 & SP3 - same every time :mad:

I've tried putting message boxes into the various closing down events and have worked out that the message is popped up after the Word_DocumentBeforeClose event and before the AddinInstance_OnDisconnection event but beyond that I don't know what's causing it to pop up and why.

Needless to say, if I install word help the message no longer appears but I don't really want to enforce this as a requirement for my users.

Does anyone have any odea what might be doin this? I'm utterly befuddled at this point. :sick: