Try checking your computer for spyware. Use popular tools like AdAware or Spybot Search and Destroy.
long ms url
I also found this during my digging about your issue. Some people are saying its defective ram. Others fixed it by cleaning spyware.
http://www.experts-exchange.com/Operating_Systems...XP/Q_20912978.html
Edit time for bed now, I think i did good, 111 posts in 1 day
zzzzzzzzzzzzzzzzzzzzzz