I have been having trouble with my GPS for the past couple days. I found this on another forum and it worked for me. I have no idea how long it will last. I powered down the phone and removed the battery for about 15 minutes. Put it back in, went outside and powered it back up. GPS was working again. I have no idea how long it will last, but this worked for me at least temporarily
Update: still working after 2 days.