FYI:
Just installed 1.2.11 and got a 'Bad referer' error in Admin, saving changes, checked the info on here and although I don't use Norton, I do use NetBarrierX3 on a Mac running 10.3.9 and once I'd disabled 'Information Hiding' it saved the changes without the 'Bad referer' error.
I repeated the situation twice for confirmation that it was NetBarrier.