I had to go through a lot of rigamarole to get SMS protect set up. When I entered my cell number, and checked the ToS box, the button stayed grayed out and wouldn't let me click. This happened both in Safari and in Chrome. It finally worked using Firefox.
I'm running MacOS 10.8, Safari Version 6.0 (8536.25), Chrome Version 21.0.1180.79, and Firefox Version 13.0.1
I got it figured out, but I just thought to let you know the issue with your website.