Make sure you are running Ad-aware by Lavasoft and not one of it's spyware look alikes.
www.tucows.com has reliable downloads of all of these programs.
Try rebooting your computer in safe mode (hit F8 as it is starting to boot) and then running these programs. Last week my paralegal managed to get a program on my machine that I had to use HiJack This! to get rid of. Ad-aware and Spybot didn't recognize it.
Good luck!