Root SIM unlock not possible after CM7 flash

[sidthekid]

applied CM7 MikOS, now unable to sim unlock the Optimus T
PUt non TMobile sim card unlock option doesnt come
tried 2945#*500# and 2945#*509# still no luck??
Any way to SIM unlock without having to rollback to stock firmware?
Hate to loose GB and the possibility of bricking the phone

 

[Cramill]

Would this work?

Backup your phone (does your recovery have nandroid backup?)
Flash a rooted stock rom.
Do sim unlock.
Restore backup.