YouTube out of sync

Does anyone have problems watching YouTube? The song is going great but the motion and lips are slowly out of sync? Even if I pause the video and let the download complete, it still happens. I have OSX Tiger 10.4.1, Firefox is my browser. I tried Safari, and same issue is at hand. My office PC (Explorer browser) works just fine. I think this issue just cropped up about 6 months ago.

Other video sites don't have that problem for me. Is it my system or YouTube? (YouTube headquarters is just a few miles away... I should walk in there and ask! LOL. Not!)

I did some research, and lots of suggestions, but I'm not risking downloading stuff or tweaking my system, when I don't know what I'm doing.