Can't speak for everyone else, but for me it is FF 3.0.13. It was worse earlier, but seemed to improve with flash 10 install; as mentioned. But then it started to surface again. I haven't really isolated the ads as I use adbolck plus (also just upgraded today, no help).
The only glaring visible message is usually:
on the bottom left, "waiting for ads at elitetrader.com..., or "connecting to google-anaylitics and connecting to edge.quantserve.com..." I see those messages as it hangs; ads are blocked by the F symbol (as in my prior posted image).
I am getting used to just hitting the back key quite a bit. But it does not always happen. Usually, one solid load that does not require back key is just entering the home page. It is when entering threads that the freeze occurs. Funny thing is, before the flash10 install, it was ALL the time in every thread --BUT-- homepage; now it is intermittent, and seems to be more related to particular threads.

I'll try to pay more attention to specifics and get back to you with details. Thanks for looking into it.
P.S. Even though they are blocked by the f symbol, as prior poster mentioned, the ads themselves load... the problem is loading any content beyond that point.