Before installing the Support Pack, you should back up your eGuide template files located in sys:tomcat\4\webapps\eguide\web-inf\templates\xsl and sys:tomcat\4\webapps\eguide\look because the Support Pack replaces these files and your customizations are lost.
If you choose the option during the Support Pack install, you can retrieve the backed-up files to preserve your customizations.