I'm trying out streaming video from my mba to my HD TV via the new airplay mirroring option but i'm finding that i'm getting choppy playback. It seems the higher the quality the more frequent the stuttering during playback. Netflix HD is a particular problem. (I'm mirroring Netflix as i'm running Netflix U.S.A through a proxy which isn't possible from the U.K on the ATV directly). Is Airplay mirroring not intended to deliver HD video or could i do something to improve matters?