Firefox probs after Thunderbird install??

Hey there,
I have been using firefox (version 1.0) for awhile and really like. I have a gmail account and thought i'd try thunderbird (version .9). Well thunderbird is all set up now, but now i have issues with firefox. If im at a web site I can only hit enter once. Like if im at ebay and do a search, then retype or add to a search, my enter key isn't recognized. I uninstalled firefox and thunderbird and reinstalled firefox, everything worked. Then i reinstalled thunderbird, then the issue is back. Anyone have any ideas?
Thanks for any help.

This is very odd since the programs operate totally independently of each other. Did you remove your Firefox & Thunderbird profiles when you uninstalled them? Are you using any extensions?

I have not been using any extensions, just one theme for firefox. I did try turning it off but the problem was still there.