Only the divx / xvid and dvd run in the built-in media player, everything else fails with "media format not supported." The DVD / DivX versions played flawlessly. The 3000 kbps xvid stuttered around 5 seconds the first time, around 9 seconds the second time, and not at all after that. That suggests that my external class 6 microSD wasn't being read fast enough to keep up, but once the data was cached, it was fine. I'm worried about the data transfer rates with the SD card, honestly... There seems to be something wrong. I hope it is my card, not the device. I will install VLC, currently the fastest alternative that I know of, and report my findings.