Honestly, I don't know what the problem with this format is in DirectRT. I know there is something unusual about it though. I can play it also in WMP. But when I try to play it in QuickTime or QuickTime Pro, it says it is not a valid video format--and that is unusual for QT to say that about an MPG file that WMP can handle. So I don't have any great advice. If it were me, I would try a few different formats until I found one that would at least be recognized by QT as a valid MPG file. I also noticed when looking at the properties across different systems there were some inconsistencies in aspect ratio, size and bit rate. I think all of this would probably be sorted out with trying a couple different encoding methods.