custom theme problem

I am trying to integrate a wordpress blog into a html/css site. I have successfully done this on 3 other sites. This one is giving me trouble:
http://www.adventurepartnerscom.fatcow.com/ap-blog/

The WP blog above should match / be wrapped by this site:
http://www.openrangeimaging.com/Test/ap/define.html

Examining the blog with Firebug it seems for some reason the #layout rule is not being found. Other rules in the same styles.css file are being found and I can’t figure out why the #layout rule is not being referenced. I think I must have the structure/sequence of the div’s wrong. I’ve tried a bunch of variations but can’t seem to get this arranged correctly.

Any help or advice will be very much appreciated.

Thanks!