This might seem like a big hammer for a small problem,
but check out AIDE.
in reply to Notification of a new file added to directory
It's a tripwire like ( minus the silly licensing ) utility
that will checksum files and directory trees and let
you know about all changes. It's also configurable enough
to ignore changes you aren't interested in.
AIDE found differences between database and filesystem!!
Start timestamp: 2002-09-23 03:30:00
Total number of files=18158,added files=1,removed files=1,changed files=0
End timestamp: 2002-09-23 03:30:04