iMac running Snow Leopard (OS 10.6)
Safari Version 5.1.9 (6534.59.8)
Flash player is up to date: 11.7.700.203
When I try to enlarge the YT video player to fullscreen, the screen will enlarge for no more that a second and then shrink back down to the original player size, but the image INSIDE the player is fullscreen! Obviously I can't watch it b/c I can then only see a small portion of the video image, so I have to reload it and watch it in the small player or, if I want to see it in full screen, use a different browser. This is annoying to say the least. This only happens with Safari and only on YouTube. Can anyone tell me how I can even begin to troubleshoot this? When I last spoke with Apple, the tech support guy said he had never even heard of something like this happening, and the YouTube site is worthless for getting help with an issue like this.