I'm close to finishing the layout of my site which uses 3 columns. The 2 sidebars use absolute positioning with the CSS "top:166px" Looks good in Firefox, but it's short by 10px in IE6 and IE7. I have no idea why. Here's what I hope is the relevant CSS:
You could easily do this with a liquid layout though I have not tried it with three columns. Your three parent-most div elements should only have width and float attributes, background-color only for visual referencing. For padding inside the parent-most div elements simply give the first-child divs instead the parent-most divs margins.
If you can't use such a layout and you just need to fix IE you should highly consider conditional comments [msdn2.microsoft.com].
Thanks for the response. I'm working on a design another developer made, and it would literally take me months to revamp it so that it would have the kind of layout you suggested. I actually resort to using a conditional comment, and it did what I needed. :-D
Always Microsoft too. Even Opera, Safari and Konqueror rendered it correctly. :-P