Span hover not showing up in IE6

This is a website i'm making for my school project.

http://opax.swin.edu.au/~569860X/brief1/website/index.htm
http://opax.swin.edu.au/~569860X/brief1/website/styles.css

When you open it up in Firefox or Opera, and you hover over the main navigation links, the span should show up to the right, above the page content. It's like a little description. It works fine in IE and Opera, but for some odd reason it wont show up in IE6.

The code i used to make it is based off:

http://meyerweb.com/eric/css/edge/popups/demo.html

That however works fine in IE6. So i'm clueless to why it's not working. Can someone help?

you are using a transitional doctype. Try using a strict doctype and see if that makes the difference. A colleage had the same issue using something similar from cssplay.co.uk and couldn't figure it out. He uses transitional. they use strict. that made all the difference.

Would that affect the display of my page in anyway? I'll try it out when i'm done with putting the content and i'll let you know how it goes. Thanks.

Okay, i tried both HTML 4.01 strict and XHTML 1.0 strict and neither of them made a difference. Urk...