Nokia Lumia :: 920 - Volume Will Randomly Go Very Low / Cannot Increase

The volume on my new Nokia Lumia 920 will randomly go very low. So far this only happens when the phone has no need to make any sounds for a long period such as playing music or videos. It goes to like volume of 1/30, but increasing it to 30/30 does nothing to increase it. only putting it to 0/30 mutes as normal but still doesn't go past 1. I have had to restart my phone several times in order to temporarily fix this issue. My phone is completely up to date with the software.