It turns out that it's not only that browser and it's not only when trying to register... a bunch of people are finding that when trying to log in the forum is looping on itself without letting them in...
"It says login successful, click here to continue, but then it just takes me back to login screen?"
or we should convince people that NIS is a totally unnecesary evil, there are plenty of other solutions out there that do not block legitimate information from being sent, plus Snitz forums are not the only sites you will have trouble with, using the HTTP_REFERER variable is a perfectly valid and widely used way of coding.