We launched the FSCN website last week & things promptly broke. The right column was too narrow in IE & the center column often overlaps the footer in Firefox.
It's frustrating, since these were not issues when we used the exact same files on the dev server.
Things I have figured out today that have squashed the IE problems:
Changed the doctype for all pages to XHTML in the templates.
Went to View > Customize > Source View & unchecked "Apply automatic formatting"
Then deleted ALL extra space in the HTML in the header & breadcrumb area. Any black space in the HTML is getting included as space by IE, even though it should technically ignore it.