I was comparing between a local and a network drive, if that makes a difference.
Maybe it was just a Windows XP glitch.
But, we both know that Windows doesn't have any bugs
It seems that the only time ED Pro would do this is after editing and clicking on save for each file.
However, I did not edit either file.
Is it possible that the menu bar had a problem?
I have experienced some weird things with my own programs, where performing a full build, vs an incremental build, solved the problem.
I'll keep watch to see if it ever happens again.