I'm not seeing an edit button for my previous post, but whatever. I just got stuck wasting the better part of the afternoon editing the CSS Stylesheet of Firefox 4 to get it the way I wanted, that's why I really didn't want to upgrade to Firefox 4, but it does work better with this site, no script error messages. That said it is still significantly slower than Safari 5.0.5 on this site.
I would recommend all Mac users to use the latest Safari for SB. What I did was made SB my home page in Safari and left it in the dock, when I want to come here I click it, for the rest of the internet I'll continue to use Firefox.
It's a reasonable solution for now, but I still don't think any site should be limited to only users of IE9 and Safari, that's just not good for anybody, the members or owners.