iTunes HD movies not working over Airplay?

Hey guys,

I tried with both v11 and v12 (nightly) to play HD (720p) movies purchased in iTunes via Airplay on XBMC. There are some single frames to see but not really a movie. I can play any other kinds of movies from iTunes without a problem. I also tried to play the movie from my iPhone - same problem.

Is this a known problem or should this normally work?

Thanks,
silent