This sounds like it could be a pre-existing hijack. Next get yourself a copy of Hijack This, from here...
If you had FF v0.8 you had this folder C:\Documents and Settings\Username\Application Data\Pheonix, which was where your FF profile was stored....
The absolute best thing would be to get rid of Norton's. Over-invasive rubbish, and in my experience responsible for more conflicts, than any...
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