Solution for GPS problems after ROM flash:
Once you've got the upgraded ROM in there, forget about VZ Navigator (at least I couldn't get it to work). Google Maps and Live Search Mobile work fine. If you have a problem getting the GPS to work:
First, go to Settings-->Personal-->Phone-->Services-->GPS (change settings): Whatever setting, change to the other and click OK. Then, if it isn't on Location On, go back in and set it to that. Soft reset after you're done with settings.
Google Maps should work either on Managed by Windows, or manually to COM 8, baud 57600. Leave it in an open sky location to get your first lock.
Live Search will only work if you have the latest build: Version 2.5.2908.31943 (or newer). The prior version WILL NOT WORK. Set GPS to Intermediate Driver. Takes a short while to lock. Then you're in business!