First thing I would try is a lens cleaner disc. If that doesn't help, I would then try a different/new nav disc. If that fails to remedy the issue, then it's time for a new REC unit.
I'm currently using a burned DVD-DL, and the first two would not read for crap. Third disc I burned at the lowest possible speed, and it's never given me a single error. Keep that in mind if you're not using an OEM disc.
Last edited by Brandon Anderson; 01-09-2012 at 10:49 AM.