Getting this a lot in Windows 7, when trying to start a program. However, you will be please to know that OpenOffice also suffers from this problem too.
It is a bit of a bother having to close and re-open the Editor all the time though.
This is a list of the running processes :
(http://i475.photobucket.com/albums/rr115/MrTAToad/runningprocesses.png)
I think, but its hard to tell, that it happens when a) in debug mode and b) some error occurs (eg Out of Dim range error, for example).
Oh!! After an error, the program usually quits itself. Very strange. I'll go investigate.
It appears that every so often the debug session doesn't actually run (even though the debug window says "start debug session"). Its at this point that the editor says the debugger is still running...
I think it's caused when the editor loses focus for whatever reason - and not on an error...