I store some user preferences in .MEM files on the NT server. There are various good reasons for using a .mem file in this case.

I had a problem with one user where the contents of the mem file were causing an error in my program so using Citrix server I remotely deleted the .mem file while the user concerned was logged off knowing that my program user module would recreate a "default" mem file when he logged in.

Well, the mem file that got created was identical to the one I deleted!
My program does a simple

IF NOT FILE({username}.mem)
  SAVE TO ..... ALL LIKE ...
ELSE
  RESTORE FROM...
ENDIF

If the OS is undeleting the file (say from cache) I would consider this a nasty OS bug. It's completely reproduceable. What do you think?