noob having issues with firefox

Okay, so I have been having lots of trouble with firefox recently and am not sure how to fix it. I'm running OSX 10.5.8 and Firefox3.5.3

I used to be able to type in anything in the address bar and it would bring up the correct website or a google search. Now when i do anything like this it gets stuck. Its not like its trying to load a site and doesn't or like there is an error of any kind. It just says "done" in the lower left corner and doesn't load anything. For example when i typed in "xkcd", it changed the url to this and then did nothing: xkcd - A Webcomic - The Search

I have also been experiencing a lot of unusual server disconnection errors that I think may be related to this issue.

I am pretty sure this is my firefox and not my internet connection or airport, but I could be wrong.

Whatever is going on, my Firefox has taken a dump and I'm not sure how to fix it.

1st, have you tried Safari to know whether it may be system wide or only Firefox?

2nd, if only FF, then I'd try moving it's preference file to the desktop, log out and back in - located at:

Users / your user / Library / Preferences / org.mozilla.firefox.plist