I would just like to share a few tips that solve a few problems I have had with WDTV live hub. I have found some MKV files play very jurky (as if a frame misses now and then). Run the video through MKV2VOB , in video setting use HDMI auto (if using HDMI) and set to auto frame rate. Hope this helps someone.
Thank you for sharing, it is a good advice for people with MKV issues.