Some div elements show up in IE but not Firefox

Hey there,
So I'm having an odd issue presently. I have a site I'm working on where I have a column that has some divs that display in ie but not in ff.

Info:
http://dev.karmel.com
The above link appears fine in ff, safari and ie.
But this link: http://dev.karmel.com/shuttle/ Doesn't display particular divs in safari and ff. But display fine in ie6+

What I've tried:
I've tried at one point to change the class names for the divs that don't display in safari and ie, but that didn't work. I also compared the markup of the divs that do display in ff to the ones that don't and I don't see anything out of the ordinary.

Advice here is appreciated. thanks.

That something works in IE means nothing. Always use the other more modern browsers as your reference.

You have 33 HTML errors and 14 or so CSS errors that need correcting. Validate for both lists.