Great wiki on XDA on how to accomplish:
http://wiki.xda-developers.com/index...VerizonAGPSFix
Read the third line from the top (redirecting you to the bottom of the page) if you want to get your GPSr working on your current release.
Use search on their upgrade forums (
http://forum.xda-developers.com/forumdisplay.php?f=384) if you want to go back to a custom rom as it has a few steps to get VZ's borking of the GPSr off the phone...
Good luck!