My wife has a Droid 3 running stock Android 2.3.4. My X2 is running stock 2.3.5. She recently recorded a couple videos that I wanted on my phone. I copied them to my PC (where they play fine with Windows media player) and then copied them to my X2. They won't play. I get a message saying "this file cannot be displayed" or something like that. I have a couple videos I have taken with my phone that play just fine. Any idea why an .mp4 created on a Droid 3 will not play on a Droid X2? Or what I can do to get them to play on the X2? ====================== I downloaded MX Player and that works. Problem solved.