Interesting. I came on here to ask about this, because I've had my tablet since January and while the lock was slow, it always locked, sometimes even indoors. But lately I haven't been able to get it to lock quickly enough to use it (as in, I get to my destination before the darned thing locks) so today I did a test. It has been sitting for hours and still no lock. I also took it outside and there is no sign of life on the satellite. Has anyone else had this problem in the past day or so? I hope my unit isn't broken, that would be a chapper.