Anyhoo, now I want to install jamal's 4.4 rom. I installed it, but the phone doesn't work. I can't make calls, mobile data isn't working, and I get no bars in the signal indicator. I restored my nandroid backup to 4.2.2 and all is well again - calls, mobile data, and signal reception.
Do I need to upgrade my modem firmware? I have the MDJ firmware, and I noticed that there's an MK6 firmware that seems to be newer. Jamal's rom actually comes with a modem, I9505XXUFNA1, but when I tried installing that with Odin, it said 'security check failed'. I'm guessing that I can only install Canadian modems?
What would be the pros/cons of flashing MK6? Does this unroot my phone? Does this lock my boot loader? I seem to recall that AT&T pushed out an update that locked their users' phones in some way. Is that what I would be in for?