I've flashed it previously, successfully, to the latest ME2 firmware, but then I installed Chainfire3D which soft-bricked it.
I recovered using Kies firmware recovery, did a factory reset/cache wipe, have rooted the phone again... but now Odin won't flash the phone!
It says "There is no PIT partition", and when I try to re-partition using the PIT file from this thread, it just says "complete(write) operation failed".
I've tried Odin 1.8, 3.04, 3.07... all the same.
The phone is currently working fine and is rooted! I just want to flash to a newer firmware, is all.