You may be missing the codec intended to be used for the video on your machine--perhaps the Windows Media Player is adapting and using something else, whereas DirectRT is not being so flexible. When I play the video in the Windows Media Player, and check File > Properties, I see that this video uses the CyberLink Video/SP Decoder (PDVD7). Do you happen to have that on your machine (check My Computer > Hardware Device Manager > Sound Video and Game Controllers > Video Codecs > Properties). If not, do you have a copy of the Cyberlink Software that was used to create the video files?