My mother gave me her old Galaxy S3 which had been network locked. I've checked the IMEI blacklist and it doesn't seem to be on 3 that you can check for free.
The phone is a UK Samsung Galaxy S3 GT-i93505, originally on contract to Orange. I used Odin and flashed the firmware from 4.1.2 to JB 4.1.1 as far as I know, so that I could unlock. Everything was successful.
I followed the numerous guides on entering Service mode > Debug > Phone Control >Network Lock > PERSO SHA256 OFF > SHA256_ENABLE_FLAG  SHA256_OFF=>Not Change > Current Command is 118630.
From here of course, I go back, hit NW LOCK NV DATA INITIALLIZ > PERSO_NV_INIT is SUCCESSFUL.
From here I wait, shut down, restart, enter my new sim, but nothing changes. Any network access is still locked. I've read on one forum that people have had success when they 'change' ENABLE_FLAG from  to , but i can't find any instruction on how to do this. I've also read that the process only works when the Current Command is 118640 not 118630, but after repeated tries the code will not change.
It's doing my nut in, I don't want to pay for an unlock code or some guy down the highstreet to unlock it when I see so many people doing it themselves...any help would seriously be appreciated, i'm new at all this.