Weird YouTube problem

[Super Dude]

For the last 24 hours, I have not been able to watch YouTube videos. Actually, they won't even load; I click on a link, and I'm stuck looking at a plain black box in the middle of my screen. I've tried right-clicking to see the Flash Player options come up, but it treats the black box no different from any other part of the page. I've cleared my cache three times, I've reinstalled Flash Player, and I disabled my pop-up blocker. Does anyone here possibly have any idea what's going on?

[jingle.boy]

The only time I've seen that is on my wife's Mac, and updating Flash then restarting Safari does the trick.

[Super Dude]

I'd like to amend my original statement slightly: apparently, the videos that aren't working are videos I haven't watched before the latest clear history/clean install/whatever else. I can view any videos that are in my history, although not necessarily in my favorites.

[El Barto]

Stock youtube problem answer: flash maintains a separate cache than your browser.  Find it and clear it.  This solves almost all of the issues.