Not sure hwo to go about this

Ebenonce

I have made some decent progress on a theme I am working with, but I am an amateur at best, and unfortunately the only tool I have is HTML Kit (if anyone even knows what that is), anyways, I've managed to get the site to look the way I want (or close enough for now) with one caveat, it's only displaying properly in Internet Explorer 8 of all browsers, The offending pages are the discussions and categories.php. To illistrate things much simpler I compiled a high resolution picture to help explain things more accurately http://www.ebenonce.com/boned.png I simply want the panel to stay always on the left, and have content on the right, I don't want 100% width Discussion pages, I've spent a collective 10 hours in two days and I think I'm at the limits of my personal knowledge, I am very willing to share this theme with the Vanilla community in return for help. http://www.ebenonce.com//CMS_Test/Vanilla/themes/vanilla/styles/default/vanilla.css here is the style sheet, I hope I have provided enough information, any help is certainly welcome, I am sincerely trying to accomplish this with good intentions.