Problems since updated to Windows Phone Black.

[Edvin Mako]

Hello guys.

Today i've updated my phone to windows phone black, and since that happend i have big problems with my lumia 520. The phone is lagging, when i listen to music suddenly stops, no metter if it is played from youtube or music player app preinstalled on the phone. Also when i talk to someone, i can't hear some words because it's interupting very often. I don't know what to do, i've reseted my phone, which removed all my stuff from phone and still not working. I have a friend who owns Nokia Lumia 520 and he do not have any problem with it.

Please help me someone, i don't know what else to do. I'm out of ideas ...

Thanks!