Also have you checked for spyware,malware and all them recommend programs are Adware and Spybot 1.3 which compliment each other.
Spybot 1.3
Adware Se
Hope they help, also run a full system scan for viruses.
Another thing I once had this issue with a website turned out to be my firewall ( yes it was nortons
) just try to access it without the firewall running, if its happening offline in your own folders then it could still be spyware.
Best of luck m8.