Why the tables? I see no tabular data on there. Please code with semantic xHTML and CSS, and if you're still having a problem with IE6 then I'll debug the code for you.
Wow Tom, that's being a bit elitist. The tables in this case are not 'crippling' or even bad per say - especially since he might be using them for things CSS can't do on DIV's, like centering dynamic content vertically... and if not, ever heard of teaching a man to fish? (and people wonder why I call it the anti-table mafia) That said there is a lot of stuff in there that makes debugging it a nightmare - multiple stylesheets, redundant and unneccessary classes, lack of sensible formatting, unneeded comments on obvious elements, etc, etc, etc. Even so it's a lot cleaner than a lot of the DIV based layouts I've seen people churn out. Give me a bit, I'll see what I can see in there that would be causing the problems. The 'obvious' causes like doctype seem to be taken care off. It LOOKS like the traditional IE 'overpadding' error which haslayout sometimes fixes, but it could be something else... A few things that do concern me: ID and a Class on body - if you need to target THAT specific, you are probably doing something wrong. DIV for what should probably be a H1, with a img inside it that should likely be loaded as presentational via CSS DIV around a para around what should be a list... The para should be unneeded. the 'unitbanner' thing should probably not even need HTML, being attached to either the menu or the H1. PrimaryNav - DIV wrapping a table just to apply a class - for styling that should be able to be applied directly to the table itself. I could go on and on here. I'll dig deeper and see if I can find what is messing up IE 6 and earlier... But I think we might be looking at rewrite territory using semantic markup.
Elitist maybe, personally I don't think I am, but as far as a professional website is concerned, there should be no need for tables unless there is tabular data that needs displaying. Of course this use wasn't on a scale of some of the terrible things I've seen been done to websites, but I just thought that so much effort had gone into the other aspects of the CSS on the site, I thought it was a shame to spoil it! But I'm glad at the end you managed to see that more than likely would need a rewrite!