This one has me stumped.  There's a file in my vault that I can't delete, no matter what I try.  The Admin account has every possible permission I can give it but the system still tells me "You lack permission to delete this file".  I've checked every section of the Admin user account and granted every permission - Administrative, State, Transistion, Folder, etc.

Is there any reason why a particular file (created by Admin, by the way) would be 'locked' from deletion, despite the fact that I've created many other files of the same type in the same location using the same method, both before and after the creation of this rogue.  Something has made this file bullet-proof and I can't figure out what.