Another fix for you JustDave:
SideBar_leftopen.tmpl
Change: <!-- echo <<<UBBTPRINT -->
To: <!-- echo <<<UBBTPRINT --><center>
SideBar_leftclose.tmpl
Change this at the end: <!-- UBBTPRINT; -->
To: <!-- UBBTPRINT; --></center>
Same for Sidebar_rightopen.tmpl and Sidebar_rightclose.tmpl
Why doing this?
If the forum has not a width of 100% its looking strange without that.

Please make the changes within the template files Dave....