Some movie sources are streamed in the highest HD called 1080p. A source of these movies can be found lurking with HackerMils. To watch them we recommend a high performance home network.
If you want to know whether the movie is really being streamed at 1080p then select "i" (for Info) on your remote control.
You will see the 1080p displayed and also information about the audio. Typically the source audio will be AAC 2.0 (Stereo speakers) or ACC 5.1 (surround sound).
You will probably get HD stutter if the audio has been encoded as 5.1, there is nothing that can be done about this at this time. You should not get HD stutter on AAC 2.0.