Have the Phantom 1. Flies just fine in manual mode....have flown it a lot already. But its never worked in GPS mode. It shows its in GPS mode when I plug into NAZA Asst and toggle the switch back & forth, etc. When turning on the Phantom to ready it for flight, I only get 1 green, then 3 red flashes (and repeat). Not more than 3 red flashes, indicating its not getting satellites' GPS signal (since it requires 4-5 or more red flashes to operate in GPS mode). What should I do?