Welcome All.
I have several Ideas:
1. I tested thousands viruses. I noticed, hat Norton 2010/2011had large problems in detecting infected files PDF. Many persons downloads infected files PDF and from blow he starts. Generally many antivirus not detecting infected PDF. I suggest to introduce to Norton 2011 (SONAR 3 or Intrusion Prevention) new rule. Big threat is from the side Infected files PDF (exploits).
2. If can introduce such function block sides net. Such function protect to before attacks Drive-by, infected scripts.
Cheers
ELWIS4745