I synced over some files from my PC, and it seemed to work fine. Played different file formats and everything (barebones video player, but I wasnt expecting much). But then I moved over some more files on my Mac, and the app crashes every time I try to access them. When I plug the card back into my Mac, they play fine. I dont know whats going on. Besides this, the app has some major deficiencies. It cant access your video library to transfer files to the SD card, and you cant put files in the app in iTunes. I could live with all that if I could just get all my files to work that should. I will probably be returning the device soon.