EDIT 06/2/2012

Hey guys,Like many T-Mobile G2x users i got seriously fed up with the poor gps K on the phone. When i first got my phone, after i rooted it I tried many of the roms here on the development forum but none of them could fix the gps locking issue. IN the past few days, the phone could not even "view" satellites at all. I was running the JUL 2011 baseband at the time. However after digging around, I went ahead and updated from the LG website with their update software. now my current baseband is M6600A-SCAUTNZ-2.0.9720T 1 [MAR 11 2012 10:00:00] MP:TRULGE_08.09.02R-MDM and gps functionality comletely came back. I have a lock under 1 min, the phone still works for calls/text, and data still works.I ran this process on a computer with Windows 7 Ultimate 64-bit. AHere is a step by step of what I did. Please read everything first before doing the steps.1. Use TGA_Gunman's guide to restoring a stock Nandroid OS that is unrooted. http://forum.xda-developers.com/show....php?t=1048274 A Stock ROM (v21e, v10f, or possibly others) is required for the "LG MOBILE SUPPORT TOOL" to work. Either from a personal backup or downloaded. Recovery version doesn't matter, but suggested to have latest CWM to make Nandroid backups & restores easier.2. (optional) After you boot into the system link your google accounts, just as you would when opening a phone for the first time.3.Visit LG's Website and download the T-Mobile LG G2x software update tool. http://www.lg.com/us/support-mobile/lg-P999 (click on the software update tab and follow the 4 steps)4.After installing LG Update software on your computer, run it, and follow the steps it tells you exactly.5.Have PATIENCE! This will take around 15 min. and patience is the key. Let it sit there and do it's thing. Make sure your computer doesn't turn off or go into standby during the process and don't disconnect your USB cable until the installer is at its last step and its tells you it's done with the update.6. Enjoy your functional gps!P.S.: Thanks to everyone for the helpful feedback and tips to making this guide better!If you are looking to downgrade your baseband or have unknown baseband error check out xBkKx's guide http://forum.xda-developers.com/show....php?t=1680292 The CM7 RC3 update has been verified that it will work with the new March 2012 baseband. If you wish to update to the rc3, apply a "dirty flash" of the 27th nightly update after it (this resolves the gps locking time back to a couple of seconds again).CM7 RC3 Update link : http://download.cyanogenmod.com/get/...999-signed.zip CM7 27th Nightly Build: http://download.cyanogenmod.com/get/...999-signed.zip