I'm running Vista and FireFox.
Check these out-could be a virus or spyware-
I run ALL of these-with NO CONFLICTS-
AVG Free anti-virus
Spybot Search & Destroy
Spyware Blaster
Ad-aware
Most of these are available at Majorgeek.com. Spyware Blaster comes from javacool.com
I just updated FireFox about an hour ago-before I got the warning from Twizted.
So far my tower hasn't 'sploded...
I'm not changing anything until I have a problem...then I guess I'll roll back the update if necessary.
Crossing my fingers, toes, legs, etc.