Mp4's won't open in XMB, ps3 reads them and knows they're there but for some reason will not open them. I can get ps3 to play them on Showtime but all I get is audio, video will just stop about 2 seconds into it. These files are stored on a Seagate 2 TB external drive. Files will play though on a smaller flash drive, so I'm guessing it's having a hard time reading off the larger drive. Any ideas on why?