I recently bought spysweeper but had trouble upgrading to the latest version. A email to them was promptly answered as soon as American came online. The same quick response on a few other queries I had as well. Clear easy to follow instruction in the email on how to solve the problem. Problem solved!
Would recommend Spysweeper as an additional measure in the fight against trojans and spyware. Picks up things Microsoft, Adaware and spybot miss.