Hi.
I just updated from a working version of Flashplayer to 11.9.900.152 on OSX 10.7.5. Now all playback is jittery, like some kind of buffering issue. It plays a few seconds, and then it reverses a second, plays a second, reverses a second. Like you were watching your reflection on a sheet of metal and then someone hits it and your reflections wobbles (jitters), cant describe it better. My Mac is a Mac mini with Core duo 1.83ghz, 2gb of ram and and intel gma 950 for gpu.
Regards,
/rror3a1