Ie 6 is beginning to fade into bad memory - but it is till out there - especially at corporate locations where legacy applications have not been updated. Mostly, it doesn't cause me a problem, I have a standard bunch of tricks I call up in a separate CSS file by conditional statement. However, I did get caught out today by a small gap between the main body of a vertically listed navigation menu, and the foot of it - held in a div with just an image in the background. After a fair bit of digging around, I found that IE6 did not like a div being opened and closed with no content. Dropping in a comment cleared the problem.
<div id="menufooter"><!-- comment eliminates gap in ie6 --></div>
Just thought I'd drop in this note; IE6 is still a PITA.