This has been a problem after the update PRI option is pressed. This also probably changed your MSL code, so if you call Sprint they will try to make you enter the MSL they have on file and it wont work. So get your MSL using BAFMSL, And follow these directions:
THIS IS FOR SPRINT Touch Pro's as far as i know...i have not tested this for any other carrier or phone so use at your own risk...
edit: tested on the touch diamond...confirmed working!
first things first
dont click on the Update PRI Button under Settings>Connections
save yourself the trouble
but if you have this is the tested method to get you back and running...it does require a hard reset so make sure to backup your data first
use the software in this link. Make sure you have CF 3.5 first (shouldnt be a problem for people on custom roms i know Juicy and Mighty's ROMS have it cooked in)
http://forum.ppcgeeks.com/showthread.php?t=43560 (needs CF 3.5)
install the program (and cf 3.5 if needed)
put your phone into airplane mode run the software. Write down your msl
go to your dialpad and type ##786#, click menu and select Reset. enter in the MSL...you will hard reset...
LET THE PHONE SELF PROGRAM!
confirm your net works...RESTART
if you need the ## codes that are reinstalled by using DCD carrier cab installed dcd carrier cab...RESTART... navigate to windows/PPST.exe and delete that file
RESTART..confirm your net still works...The option to update the pri is still there but pressing it will do nothing...
Test your ## codes by going back to your dialpad and either pressing ##786# or ##3282#
http://forum.ppcgeeks.com/showthread.php?t=64718