I suggest you try Spyware Search & Destroy if you haven't already. It finds more adware than AdAware, so give it a shot. Run housecall (http://www.antivirus.com) while you're at it. If you still find nothing, just reply so we can try other things.

"Stephen Wolfram is the creator of Mathematica and is widely regarded as the most important innovator in scientific and technical computing today." - Stephen Wolfram