It may be a width problem… IE and Firefox tend to see attributes differently. Some things (like padding) might add to the overall width of a division in IE, while not changing it in FF. Do you have a separate ie.css stylesheet? If not, check out the beginning of this post for instructions on how to add one. Then you can fiddle around with the widths of different divistions, and see if that fixes things.
Another possibility is that there is a line somewhere in one of the divisions that doesn’t quite fit inside the padding of that division. In firefox, that line will just extend into the padding (or even right on out of the division) whereas in IE, the line will stretch the division. It could also be a picture. Try making an ie.css file and messing around with padding too…
