I am using a iPhone 3GS purchased in August 2009 with OS v3.1.3. With the phone connected to the 3G network, the Edge network or WiFi network in my home, the phone is unable to determine my location (in Yelp, Google Maps, etc). Similarly, when I launch AT&T Navigator (for which I pay a monthly subscription fee) my phone is unable to connect to GPS. Is anyone aware of a bug in the new operating system that may explain this? Is anyone else having this problem?