IE is the debbil!!
After taking over one of the websites in my new job, I found a bug in IE 6, which did not appear in IE 5.5 (apparently it is possible for Microsoft to get worse) where when a main div was separated into columns anything in the columns was not displayed. After hours of searching and messing with the CSS a colleague suggested setting a width for the div in which the columns lived. IT WORKED! Such a simple solution after hours of searching was both satisfying but also very annoying.
In summary, will someone please sort out the IE developers…