I experienced this "Access Violation" many times in the past, particularly after installing a newer version of BIAB. Somewhere I read that this was caused by having duplicate files of "bbw.exe" and sure enough everytime it would happen I would check and find more than one copy in my BB folder. I would delete the duplicates and everything would work fine again. Just make sure you don't delete the one that connects your shortcut to the program. You can usually tell by the date it was installed.
Hope this helps!