CSS Box Model Bug? Advice Needed!?

http://67.43.120.140/kurt The above link is for a website I'm working on for a friend. It relies on two style sheets (2column.css & submenu.css). There is also a javascript file (ieHover.js) The 2column sheet is not the problem. Somewhere in the submenu.css sheet I've created (because it wasnt there earlier) a cirucumstance whereby the submenu box is multi-line on IE6. It looks correct when viewed with Mozilla. The submenu text elements should be horizontal, single-line. The submenu.css sheet is a merge of a CSS tab menu and a CSS drop-down menu. I used internet-available code, so some naming conventions (ie: liRenaissance) are not my doing. When I tried to change the names of those it made for a mad-house, so I've opted to leave it in place till I find a way to remove it without confusing it. Also - and I'm not sure what to do about it - there is a "focus" issue - relates to what tab has the focus when the page is loaded when no hover state exists and uses .on and .off classes. I've now removed/change all but two display:blocks. The remaining two when changed dont seem to fix the proble - but do create other large problems. :( Sorry if the link temporarily flaked out - we have had two minor (brief) power outages today that have temp. taken my webserver offline. At the moment, its back up.