I've recently been working on building/designing my personal site according to XHTML and CSS standards. So far, nearly everything has gone smoothly and I've learned tons about standards while having lots of fun. However, I have encountered one small problem: a part of the layout in my portfolio section breaks when viewed with Internet Explorer 5 for the macintosh. I've tested the site in IE5/NS6/Mozilla/Opera on a PC (the design is hidden from older browsers) and IE5/NS6/Mozilla on a Macintosh, and it appears that IE5 for Macintosh is the only browser in which this particular bug occurs. I'm not sure what's going on here, probably something to do with my hacked-together code for this particular section.

Here's the actual page:
http://www.digital-hearth.com/portfolio/web.html

Here's a page with screenshots (.gif) of both the correct version, the buggy version, and the parts of the css and html which controls the presentation:
http://www.digital-hearth.com/portfolio/incorrect.html

Here's a link to my main style sheet:
http://www.digital-hearth.com/style/mainstyle.css

If anybody has any suggestions or tips on how to hack through this little bug (although it might not be a bug, could just be my crappy code), they would be utterly appreciated. Failing that, if there is somewhere else that I should be asking this question, perhaps you could point me in the right direction? Thanks.