I have my XBox 360 set up as a Media Center Extender for my Windows 7 desktop. SD quality avi videos stream fine to my XBox, either though the video library or through Media Center Extender, but when I try a 720p mkv file, the frame rate plummets and the A/V sync is completely lost. I don't want to transcode or switch container formats (mkv isn't supported by the 360), but still want to stream.
Both my desktop and 360 are plugged into the same gigabit switch, which is plugged into my ISP supplied modem/router. The video plays fine on my machine in a number of programs.
Considering that I should have more than enough bandwidth to accommodate this video, why won't it play back properly?