Use a php include in the ubbt_footer.tmpl and leave the html footer empty. I do this on mine.
UBBTPRINT;
include ="/orn/common/mainfooter.stm";
echo <<<UBBTPRINT
--
UBBDesign.com: UBB â„¢ customizer, webdesigner and custom graphics creator.
Creator of the JCTemplates used in the ubb.classic â„¢ software.
Addons & Graphics Installation services and custom add-on creation available.
Contact me