Buggy Bug Bug - CSS Divs

Hi y’all! It’s been a while since I’ve posted. Well, might as well cut to the chase. I’m working on laying out a certain website, here:

And it seems to work pretty well in both:
[]Firefox 1.5
]Firefox 2.0 Beta
[*]Internet Explorer 6.0
[/list]However, it has not been working on Firefox 1.07. Many of the divs that were floated on the left, pushed to the right of the leftwardmost columns have been pushed to the next line.

Anyone know of some bug or hack to fix this?
Thanks :snug: