I have been using my 770 for a while now to watch BBC video podcasts, and it works great, they are in mp4 format, and work great in the normal 770 video player. Now i download the CNN podcasts that are in m4v format and they do not open in the stock video player, they say that the video format is not recognized or something like that. They also do not open in Mplayer, but if i change the file format from .m4v to .mp4 they will open and begin to play but are super choppy and i cannot even get the other video podcasts that work fine to play at all, they just show a blank screen.

Any thoughs, i have the most recent version of Mplayer and i have no other applications open...