Bug Question

I have a question about a possible bug. I have run Norton 2005, adaware and I still can’t figure it out. My home page keeps getting switched to this letsroll911.org I go to my settings and switch back to yahoo and apply. Then it automatically gets switched back to this letsroll thing. CAN ANYONE PLEASE HELP ME???
Or point me in the right direction for help? Thanks,

Try to run Spybot, Adaware and CWCShredder to find spyware on your system that does this.