Included menu looks different on vb 3 and vb 2

[kvnband]

OK - Here's the story. My client has a website that is currently running VB 2.x. I'm upgrading it for him to vb 3.6.7 but I'm running into one single problem.

On his forum (running 2.x), he includes header.shtml and footer.shtml in the phpinclude template and it looks like

http://www.cappersinfo.com/forums

HOWEVER, when I create a new plugin in the vb 3.6.7 install, and include the same file, it looks like

http://www.cappersinfo.com/kevin_backup

It looks almost identical, save for two very annoying things:

1. The side menu has no background color for some reason.
2. The side menu doesn't connect to the footer like it should be.

I've tried copying the CSS for the side menu directly into the main css for the template, but it makes no difference. Any help is appreciated on this (as it's driving me crazy)

Kevin

OK, I just tried changing the CSS element name for the menu from nav to menunav123 (thinking that the word nav was conflicting with VB somehow) and it made no change whatsoever.
So I'm totally clueless on how to go about fixing this. It's pretty urgent, so any advice is appreciated.