Ok, I have to say, I might not get this right, because I dont know the terminology, its just something I am picking up as I go along.
I made a copy of the phone, and saved it to my laptop. I used CWM, rooted the hone and flashed a ROM, called Dmodv6. Its US based ROM, which is running ok, but causing problems. I used CWM to flash the ROM, and it just said that it had stopped the installation, nothing else. Something I didnt know was that I had to uninstall any APPs that needed root to be able to do a new install. That is something I just found out. The Baseband version ends in AMJ2, but I cant find a ROM that matches that. My carrier is EE. The ROM I have now, only recognises T-Mobile-UK, which from what I can understand is the US version of T-Mobile in the UK. I keep loosing that too, and have to reconnect all the time.