Display error with SMF/Joomla and IE6

[nxparadox]

I just installed a cool new SMF theme that I dl'd from here (techhead), but the top menu frame and buttons shows up out of place when I go to the forums of my website with IE 6.  On rare occasions it will fix itself after you go there, and/or if you refresh, but if you go there again it is all FUBAR'd again. 

Any help would be HUGELY appreciated!
thx 

Here is the website:
www.fairyportal.com

Here is the error code I got from the SMF logs:
8: Undefined variable: sidenav
File: /usr/local/psa/home/vhosts/fairyportal.com/httpdocs/templates/rt_versatility_ii_lime/index.php
Line: 164

My specs:
Joomla! 1.0.10 Stable [ Sundown ] 26 June 2006 00:00 UTC
Your Joomla-SMF Integration version is 1.1.4.2
Simple Machines Forum 1.1RC2
Community Builder 1.0RC2