The identical thing happened to me a couple of days ago. Are you
getting an error message when you try to access the Junk Mail Filter in
your menus, and then you can't change any settings?
I have tried both a Typical and Advanced rebuild of my identity
database, but no change. I've gotten rid of my Entourage preference
files, and still no change. One thing I figured out is that it's not
the application itself, because if you rename your database file and
then open Entourage, it opens with a clean slate and creates a new
database file. That one allows access to the Junk Mail Filter again.
So, it seems the problem is some type of corruption of the database
file itself. Now, what to do about it is a different story...
Wondering if this has happened to anyone else. I assumed it wasn't a
virus, but the coincidence makes me wonder...