Same problem with Lumia 1020 with Lumia Black update, at some random point all music apps and video apps including default players will not respond to changes in volume, if you skip a track the volume currently set will be used but if you change the volume while that track or video plays then nothing happens. I have seen that all my games and emulators respond to volume changes normally even though the 'bug' would be in effect. A restart does temporarily fix the bug but sometimes just playing one track sets off the bug again.
I cannot afford to restart my phone each time I need to play another track or video and if I did that my 1Gb+ game downloads on 'only wifi' would start downloading from the begining of the file again, the downloads do not automatically resume and if you let the battery run flat out then all the dowloads would begin from scratch again. Maybe Microsoft and Nokia should speak to the guys who created the "Free Download Manager" for PC for some programming 101 lessons. It is cumbersome to manually resume a 1Gb+ file download over WiFi which stops working and does nothing every two or three minutes, at times having to stop and restart the WiFi connection again, besides, the WiFi on my lumia is slower and inconsistent than that on my notebook which never cuts and does not give me a job of continously and manually resuming frozen downloads!
So much for our monies people! This baby cost me thousands of rands and what I get from it is stress and disappointment most of the time, given that Microsoft and or Nokia don't seem to care about rolling out fixes quickly if at all or at least implementing the features millions of customers are in dire need for... I guess next time I would rather go for an iphone, or a samsung or some other android crap, those guys don't cry as much... :crying: :crying: :unhappysweat: :angry: