I have never experienced those problems, I'm guessing you were also one of those people who experienced slow scrolling.
I can only come to the conclusion that your computer sucks ass. From my understanding Firefox adjusts itself to use the maximum performance of whatever machine its on and that's purposely paused animated elements to prevent the slowdown of your machine when playing the embedded video.
My computer doesn't suck ass in the least.. I have 2 gigs of ram and an Intel Core 2 Duo Processor, which is a decent to good processor. And I doubt graphics card has anything do do with it, but I have a great Nvidia GeForce 9750 GX2, which is a very good card. I also have 600 gb of HD space and a high limit on my FF cache so it couldn't be related to that. Need more? I'm running the newest version of Firefox on Windows XP. My computer pwns, don't assume about it.
Now this is where I say, "that was a completely random and unneeded response to a response that was obviously not directed at you."
Who was it directed at then? The post above yours said "I have no more problems", and my post was the first post before his referring to an error.
It doesn't say "I have no more problems" at all, if you even read his post. He simply stated that the problems he has aren't as severe as the problems araknidude is experiencing. I was just continuing on that conversation in response to him as well.
If you were to fully read my response you'd of noticed I didn't at all reference to the problems your having.