Run adaware and spybot then do a virus check, it sounds like you have a virus or trojan.

You can do an online scan here if you find nothing yourself...

http://housecall.trendmicro.com/

I've also used this..

http://www.windowsecurity.com/trojanscan/

__________________
~Kath~
Always judge a person by the way they treat someone who can be of no possible use to them