I just downloaded the latest version of Firefox and Flash on my Snow Leopard machine, specs on my sig. What happens is that videos have a center block that is out of sync with the rest of the image. This doesn't happen on my old version of FF. When I go full screen it is OK, but you don't always go full screen for a quick video.

Does anybody have a fix for this? In the meantime, I'm going to pull the old copy from Time Machine back as this is a very annoying bug. It makes any Flash video unwatchable.