Persistent Trojan.!?

I had the same problem. The only solution was to run avg after starting the computer and let it quarantine the trojan. I then did a backup of my files on cd and reformatted my hard drive and reinstalled all programs. I know this is drastic but it was the only cure I could find. All is well now and I have purchased AVG and the shield now will detect and block incoming trojans. Hope this helps.