Interesting yesterday and today it was impossible to get sound.. Tried everything, starting mediaplayer before and so on, no restart of the whole phone though. When I reed this I directly went in(auto login), no sound, and then log out. Started program again, logged in with my credentials and sound is now working.

I have also tested with my other phone, but there I had to login, and the sound worked. Will try that tonight with auto login and see if the problem occurs there also.