This is a long shot, but I know the new "protection suite" my wife's computer has asks her to approve all registry changes, firewall access, etc... I wonder if there's some settings, approvals, etc... that you need to accept or approve in your new anti-virus program that might be blocking some things from showing. It's unlikely, but it's the best I can think of at the moment.

I'm guessing you've searched online for answers too.