I saw the safe mode feature but didn't try it. Nobody on the forums has mentioned that it fixed anything, anyway.
Opera is working fine for me.
And yes, most people report their connection problems started with version 3.5x. I didn't want to downgrade to 3.0x, as I felt that sooner or later I'd want to update and FF would fall down again.
Plus, Opera seems to be blocking those annoying Netflix ads pretty well, so far. My biggest peeve about them was that while setting FF to open things in new tabs, the Netflix ads would open in a new window. Then, when I shut down FF at the end of the night, the Netflix window would still be open, and the next time I launched FF, all my previous tabs were missing, and I'd have to populate them again. Not a problem, so far, with Opera. Plus Opera has a more configurable pop-up blocker.
I used to work for someone who went to Netflix and scored big. I really didn't care for that person (all hat and no cattle) and have been turned off on Netflix for that reason. Their annoying pop-up ads only strengthened my dislike for the company. I prefer to "own" the DVD's I watch, anyway.