cant play 60fps vids on youtube unless i shrink my browser

So, I haven't found a single other person on the net with my exact same problem. If I select a vid in 720/60fps (1080/60fps is worse) and play it in either default, theatre or full screen mode it won't play smooth 60fps. I can absolutely see it's playing in 30fps or less. But if I shrink my browser (chrome or even Firefox both up to date) down to 1/4 size of the desktop, I can see it play 60fps smoothly.
My specs:
2009 Mac mini
Lion 10.7.5
8gigs ram
download speed 30mbps avg.
32" LCD tv as my monitor set to 1920x1080 60hz using VGA input from Mac mini

I CAN play 1080/60fps gopro vids (25mbps bit rate mp4) on my harddrive perfectly with QuickTime or vlc.

Your suggestions are much appreciated

32" LCD tv as my monitor set to 1920x1080 60hz using VGA input from Mac mini

Click to expand...

Just a WAG here.... you're using an analog signal to your monitor. You would be better off using DVI or HDMI which would provide a digital signal to the monitor and perhaps clear up the problem you're experiencing. In any event, you'll get a much better output.

Using a VGA ouput, you are having the computer convert the ouput from digital to analog and then to an LCD where the TV has to convert the analog back to digital in order to put a picture on the screen. That was enough to convince me to give up using analog video input ports many years ago.

While VGA is capable of doing what you're trying, it could be just a poor quality VGA cable, could be the board on the TV is having an issue with the conversion of that fast a motion back to digital where it may not have an issue viewing a more static computer image.

If you don't already have another VGA cable to try, I'd definitely suggest you go HDMI instead.

edit:
If the issue is only with youtube vids while other vids (Netflix, Hulu, etc.) at the same output play just fine, I'd suggest the issue is youtube and nothing to do with your system.

thanks for the replies, I learned a few things about analog and digital I didn't know before. Yes the problem is only with watching YouTube videos trying to play at 60 frames per second. Even though Netflix does not stream at 60 frames per second, it plays fine. I tried reducing my desktop resolution from 1920x1080 @60hz down to 1280x720 @60hz then went back to YouTube and played the same 60fps vids and they looked glass smooth gorgeous. Hmmm.