Firefox 2.0.0.17- multiple windows?

for some reason when I pop open FFP 2.0.0.0.17, it opens 100s of firefox windows and I only clicked once. I've downgraded then upgraded and the issue seems to have corrected itself, but it pops up no and then. I constantly have to upgrade and downgrade my ffp. I haven't upgraded to 3.0.3 since it runs abymsyally slow on my thumbdrive