Sorry for the delay...
We need to reset Firefox to defaults...Before we do so be sure that you have all of your passwords saved someplace. There are many many files related to Firefox and finding the culprit will be like finding a pin in a haystack so this is our best option.
Once you have all of your passwords saved someplace safe do the following...
Go to Start >> Run >> copy/paste the following text in the Code Box to the Run bar and press OK
You will now be looking at a box showing FireFox Safe Mode.
firefox -safe-mode firefox-safe-mode
Check all the boxes
Press Make Changes and Restart
Now open Firefox and let me know if you are still being redirected.