As of August 18, a large amount of Android devices in upstate NY on the Verizon network have not been able to use Google Nav or lock onto GPS satellites. Verizon, as is typical of them, has not officially admitted to the issue. Some tech support personnel try to blame Google, others are saying it is an HTC issue (since it was noticed first on the Incredible and Thunderbolt).
My local store rep told me that it seems to be a result of the 4G rollout, which is more likely, as the issue began the same day. I have three affected devices in my house, a Thunderbolt (unrooted), an Incredilble and an OG Droid (both rooted and running custom ROMs). My Xoom, which is WIFI-only (hence not on the Verizon network) is working correctly.
If you are in the affected area and are having an issue, please make a post on the Google Mobile forum posted below. In that thread, you will find ways to contact Verizon tech support and have them open a ticket. The more people who report the issue, the more likely Verizon is to acknowledge it and get it fixed.
Phone located in USA shows GPS Location moving thru SPAIN? Has my Phone been Hacked? - Google Mobile Help