I have a compass problem on my 1520, no apps can use it or detect it. I ran the nokia product support tools and put the phone in test mode - it passes all tests including the magnetometer test. So this is some kind of software issue.
Side rant:
Between this issue and other software glitches involving the rotation getting stuck in landscape on the lumia camera I'm getting fed up with windows phone. I've been exclusively a windows phone user since 2008, and WM 6.1.... WM10 will be my last chance for Microsoft
/rant