Firefox 3.6 has actually proven to be quite buggy in my recent experience. It has odd errors wrt semi-valid SSL certificates too. It's a shame, but lately, Firefox has turned into every bit the pig that the browsers it was trying not to be were.
Bob, I think the site looks great, don't sweat the minor bugs like that, I think you're definitely on the right track here (and enlisting a bunch of detail oriented modelers is far more QA than I'd ever wish on myself, but probably a great idea).