What spyware are you seeing on Firefox? You sure it's not the normal IE spyware that's so prevalent, since IE is still on your computer, regardless of whether you're using Firefox to surf?
And that type of spyware is usually a result of a vulnerability in either Java or Flash, which unfortunately Firefox/Mozilla have no control over. Turning those off would make you safer... but then again... you wouldn't have all the pretties on the sites you visit. It boils down to whether you want to surf safe, or convenient.
Graphic Design / Photography / Web Design