hi there, since i upgraded to ml i have troubles with my sound/video mostly on youtube. i have an iMac 27 mid 2011 i7 ok if i watch youtube videos in hd after about 3 - 7 videos (think about 15 minutes) the sound an the video begins to stuck and you are unable to watch a video smoothly. then i need to reduce the quality to watch the video smoothly. does anyone have a similar problem like me? could it be a cache problem? thanks for replies edit: so it doesn't matter if its high or low quality. i think the major point is, if its fullscreen or not. regularly i can watch a youtube video about 2 - 5 minutes, after that it begins to stuck till i leave fullscreen view.