-----Original Message-----
Try running regmon or filemon from www.sysinternals.com as
an admin while a normal user saves their signature. Make
note of where it saves that signature and then see when
the file/registry entry is being deleted. You might have
a policy that is deleting it.
We had this problem a few weeks ago. It just went away!
Matthew suggested running regmon to me and I tested it in
a lab environment. Seems like a really nice tool.
I know that "just went away" does not help you! Sorry.