I've had my S4 for about a week now and only put music on it a couple of days ago (I had been waiting to get a micro SD card). It's a Fido SGH-I337M, 16 GB. I rooted it using Motochopper. There's a strange thing that keeps happening every time I pause an MP3. After pausing, when I try to unlock the phone from the lockscreen, it freezes up and crashes (happens every time). Sometimes it ends up rebooting. Now, this only happens with MP3s. It does not happen with FLAC files. I've searched high and low on google for other instances of this and have found nothing. It seems like it's a software bug but I tried restoring to factory settings and it continued to freeze up. I tried unrooting it and had the same result. The crashes happen whether the MP3 is on the phone storage or on the SD card. It's not due to any of my downloaded apps, because after doing a factory reset I was able to recreate the MP3 crash before doing anything else to the phone. Anyone know anything about this or can offer suggestions to try fix this? I'd like to try to resolve this before I take it in to get it exchanged.