Wasn't sure where to post this. Posted it in reply to my own HJT thread, http://www.bleepingcomputer.com/forums/t/202342/search-results-redirected/
, but I wanted to get the word out a little bit more.
If you are having google searches redirected in Firefox 3.0.6, but all of your malware scans are coming up clean, try the following: go into your firefox installation directory, to the Extensions folder (eg: C:\Program Files\Mozilla Firefox\extensions).
One at a time, cut a folder out of this location and paste it to the desktop.
Then try to search. Click on like 10 results and see if you get any redirects.
If you do, you've removed the wrong extension. Put it back.
If you don't, you've just identified the extension that's causing the redirects. Put it back and test again, just to be certain.
Once you've identified the problem extension (you've positively verified that when it's out of your extensions folder you get no redirects, and when it's in your extensions folder you do), delete it. If it gives you trouble deleting it, move it and rename it for now, and look for help deleting problem files. Your problems should be gone.
note: I have been told that two addons for Firefox, Web of Trust and NoScript, will prevent this problem in the future but I have not used them and cannot vouch for them.
Also: I saved the little bugger in case anyone wants to see it.