Once you figure out the unlock code u can go into security settings and change the code to whatever you want and it should stay the same no matter the update. I had it all 0's since 3.4 and never had any problems getting in. Now that the 3.6 came out I can't get in, about to try this new code and maybe I can change it again without issues.
Another confusion is, I did turn off automatic updates so this is very upsetting right now.
On another subject, anyone figure out how to play sf4 or any other game online? I can do youtube and everything just cant play people online.