It is OK.
I would perhaps redesign the header and footer, using gradient colours for the orange, so it fades to a background colour for the body.
Instead of putting hyperlinks throughout the text in the body and having a menu at the bottom, I would consolidate everything in to the main menu in the header. I feel having navigation in the header and footer, is very messy.
Also don't discount IE6 users. Many still use it. Especially in companies where they have software reliant on IE6. So for instance, if the government in NZ has a cycle to work scheme for giving tax breaks to workers buying bikes, you are effectively neglecting that entire market, as they can't browse the site from work. A lot more than 1% of users, use IE6. As I said, up to 50% in your demographic or more could use IE6.
Yes it is annoying when IE6 goes in to quirk mode, but stick with it.