An MPEG-DVD is a DVD-disc with MPEG-files burned as a regular data-DVD.
To try out the MPEG-DVD compatibility of the NorthQ 7100, I burned a DVD with the same structure as the CD I burned to test MPEG-compatibility. Then I inserted it in the DVD-player and hoped for the best.
To my surprise, the NorthQ had no problems with this disc! It displayed the MPEG pictures and everything behaved almost as in the MPEG-compatibility tests! he only difference was that the 8 Mbit/s CBR XSVCD (XSVCD_8M.mpg) also played without problems.