I would hate to see this thread cluttered with posts of "Well, it worked for me," but seeing how few posts there are, I suppose it's ok for me to do it.
Mr. Goldfish worked fine for me -- no jitters. Other than that, I can't offer much more than I agree with things already said: my guess is that it's the Flash player.
Especially with Flash, I'd normally immediately blame Windows, running something stupid in the background, choking the player, but since you've done restores... I'm at a loss.
I hope you get this resolved, because I, too, would be sad if this was the end of your games.

--mister. jones