Well, I have heard that this problem occurs in 64bit based machines and code running within the Form load event. Anyway, I don't know how Microsoft have not announced a patch or something to fix this issue. It seems to me very strange. Using a Try/Catch block is good, but precisely, several times you don't notice about these possible erorrs until CLR pops up with exception. Besides, I'm not sure nethier it is just in the main Form Load event nor in every forms your project has. Remember that when CLR detects an exception it first goes backwards within the code to find some exception handler, and it's possible that it was called (in some moment) by the "bad" Form, so...

Well, let's see what happen. If any information about it gets me, I will post it here.
Regards.