Hello all, just curious as to whether anyone else has this problem, since updating iTunes to 10.4 when I play movie full screen on my 2011 21" iMac every three or four seconds the movie stutters, this only happens on full screen , when the iTunes control bars are present top and bottom this doesn't happen and playback is fine, it only occurrs full screen without any distractions. I am running lion by the way, thanks.