It was NCSettings for me, too. Uninstalled it and it fixed all of my issues with screen brightness.
I'll just use Intelliscreen X for the lock/NC settings, I suppose. I liked NCSettings better, hopefully they'll fix this issue before too long.
Being new to the JB community, are these bugs usually fixed relatively quickly or is it more of a "deal with it" type of attitude? I guess it probably depends on the dev.