Had a wee problem with one of our pcs last week. Its protected by Spybot and AVG, both updated and scanned daily. Anyway, a bit of research online told me it was a trojan I was having problems with but PC Tools Spyware Doctor would manage to find and heal the problem. Right enough it did (and found some other bad stuff as well). Its free if you download Google Chrome at the same time (or any other Google tool). Heres the link anyway, and hopefully it will help someone.