I just got a replacement xv6900 and while the GPS was working on my old one i can't seem to get it working on my new phone. I believe it has something to do with me flashing the leaked verizon rom.
The post you refer to -
You'll also want to read about how VZW severely limits GPS functionality and how to overcome the limitations.
http://forum.ppcgeeks.com/showthread.php?t=47174
Appears to be not working, is the valhalla fix the only way i can get the GPS working again?