UPDATE:
After switching ROMs and Kernals a few times, my GPS stopped working and the fix below didn’t help anymore.
chui101 created an amazing software patch that seems to fix my GPS issues without any complicated settings. Try it out if you’re still having trouble with your Vibrant’s GPS.
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The Samsung Vibrant is hands down the best phone I’ve ever used, however it has a shortcoming in the GPS department.
The settings that come preloaded on the Samsung Vibrant for GPS are not optimal for trying to quickly connect to GPS.
Before making the changes below, I could only connect to GPS once per reboot of my phone.
1 – Disable “Use Wireless Networks” – Settings / Location & Security
2 – Dial *#*#3214789650#*#*
3 – Under “Application settings” Change “Operation Mode” to MS Based
4 – Under “SUPL/CP Settings” Change the SERVER & PORT to supl.google.com and port 7276 [ Do not use www. in front of supl]
5 – REBOOT
I also installed “GPS Status” which has a tool to Reset the local AGSP data, and redownload new data to help assist your phone finding the correct location.
The original GPS settings were:
Operation Mode: Standalone
Server: www.spirent-lcs.com
Port: 7275
After making these changes, I could now connect to GPS 3 different times, connecting under half a minute, all without requiring a single reboot of my phone.
Source and other alternative code if the above code doesn’t work on your firmware.