I have various MP4 video files that I ripped from other sources. on some, I just copy over to my Motorola Droid 2 and they play fine. but I just got some from a friend, and the error "the file is a type which can not be played" comes up with all of them. Any suggestions on what I can do? I don't know how they were originally ripped, my friend just sent me the direct MP4 files. I used to get AVI files and converted via a video conversion software I own, but since these new files are already in MP4 format, I'm stuck. The videos are seen and heard fine on my computer, but doesn't not on my Droid. I found some links on this site but nothing quite answers my specific problem.