Ie6 & css

I recently built out the template for a site I’m working on. It views correctly on Firefox, IE7 & Safari(At least on my end). The problem is with IE6. I’m no CSS expert. Basically, I have no idea where to start troubleshooting and thought someone here might be able to notice something obvious that I am unaware of. The site is at:

http://www.launchpadserver.com/mnc/dev/

and the main style sheet is at:

http://www.launchpadserver.com/mnc/dev/styles/style.css

Thanks for any help!

DC