Glad you got it nailed in the end - I must confess that the scenario you describe didn't really occur to me. I assumed (yep, me too) that the line of code was executing, but not succeeding.

I don't know how familiar you are with the Access & VB IDE, but in future, if you set a Breakpoint on the relevant line of code you're interested in, you can 'see' it execute.

Finally, I think newer versions of Access (2k and XP) are smart enough to work out what event handlers are attached to which controls when you compile the project.