Video stutter in Youtube on Chrome

Hello all,

I am having a problem with Youtube videos when viewing them in Chrome. On higher resolutions (480p and up) the video starts to stutter (not even lag, literally stuttering), audio remains OK. I have tried updating Flash, but this does not help solve the issue. This does not happen in all videos.

And this problem started appearing only after an upgrade to Mountain Lion.

Any help?
Thanks,

Petar