No GPS problems here, I have used my phone to log runs, bike rides and navigate with the GPS and it has worked fine.
Looks like you might have just received a dud, hopefully the next one will work.
Interesting, I instinctively put my phone on vibrate first day I received it because I hate it making sounds when I'm at work so I guess that also turned off vibrate even though the volume is still on for videos and music. I always thought it just didn't have a shutter sound because I've never...