This problem was bugging me for a while now and I've just been using IE whenever I needed to view a site with Flash content. It finally annoyed me enough to figure out what the problem was and find a fix. The obvious step of reinstalling the flash plugin didn't work. I finally tracked it down to a problem with Adblock. Wasn't very hard to find because anyone with Adblock installed looking at Flash 8.0 content is having this problem and there's a lot of talk on the adblock and macromedia boards about it. Anyway, the fix is in the adblock preference, uncheck the obj-tabs option and the flash is back. The downside is that this allows all Flash content through though it can be blocked and unblocked manually with ctrl+shift+f. Of course filters can always be set up for the really annoying stuff.