Did you by any chance check out this thread I mentioned above to see if it would help:

Also check out the thread called "file upload validation problem" by lanerj jul 4,2000

This thread includes some code to force minimum upload file size. Perhaps this will force them to have to
add a photo to be able to modify their record?

I know for the single upload mod there was a line which would verify a file was uploaded but I'm not sure how that would be modified to work with the multiple file upload mod.

Unoffical DBMan FAQ

http://creativecomputingweb.com/dbman/index.shtml/