I have an addin which handles events for certain workbooks. It makes
itself available through a menu bar. During the process of opening a
new workbook, it is supposed to catch the Workbook_open event and
check if the workbook being opened is something it should handle, if
it is, the menu is shown, if not, it does nothing. The addin also
handles other events such as double clicking on cells .

After some period of using the workbook with the addin enabled, it
seems to just stop handling events. I am checking that
Application.EnableEvents is still true and it is. But all events are
unhandled, including(it seems) workbook_open. Now, the workbook_open
event that is defined is in the addin's workbook... but it seems to
handle everything most of the time.

If anyone can give me a hint at what to look for I would appreciate
it. Sorry, I can't really post the code due to length and corporate
restriction. I'm just trying to figure out if there's a VBA guru out
there that has seen this sort of behavior before.

Thanks