19-03-2012 12:29 PM
Did it happen after an update immediately or just like that? Try to reset it. You even should have a reset button on the bottom. You will lose your personalized stuff and settings, so make a backup first, a manual one, with all the hidden files.
Maybe your GPS receiver is dislocated or gave up. That is another possibility.
17-06-2012 07:17 PM
What is the software version on your device and which device is it?