percentage difference between ie and mozilla

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I made a page that has some divs that I would like to line up next to each
other. I used percentage values to set their positions and sizes, but in IE6
there are breaks in between them and I can't figure out how to get them to
line up. The page displays fine with Mozilla, and it also does not have this
problem if I use pixels to specify the position and size. The page is here
(http://cwp.byu.edu/red.html) and the stylesheet here
(http://cwp.byu.edu/quickred.css) so that you can look at them. Please tell
me if you know what the issue is here. Thanks.