First couple of days I had my M8 I noticed that my phone would sleep/hibernate like normal for a while then suddenly stay awake for the rest of the day until I reboot. Then after a while the phone would stay awake again. Checking on that behavior again I notice the time it stayed awake was approximately the time I would receive a phone call. Looking for wakelocks I did notice [d.process.media] was listed as using 148mb of data but it didn't seem to be keeping my phone awake. I moved my ringtones/notification sounds to my phone and ejected the SD card and used it sans SD card the last couple of days. Now my staying awake behavior is gone and my battery life has improved. Not sure if something was funky with my SD card, or what but the behavior is gone. Going to clean it off and put it back in and see if I see that behavior or not. Wasn't sure if anyone else has seen something similar with their phone staying awake constantly.