I just upgraded my Note I to JB 4.1.2 and lost all ability to play mp3's. I have tried using Player Pro, Walkman, and Ambling Book Reader. They all return errors saying that the file cannot be played. I have reinstalled the apps and rebooted to no avail. I also reformatted my SD card and reinstalled my music and books, again to no avail. I presume that I have lost (or corrupted) my codecs. Any help is appreciated. Thanx in advance.