I have the same problem. Today I tested SiteAssist pro. I have windows 7 64-bits, DW-CS4.
I first created a dynamic site in DW. Then created an empty php page. Then run the siteAssist pro BUILD SITE using
DESIGN: deep jungle
The rest choices are all defaults.
The generated site assist pages all have the following code:
<!-- InstanceBegin template="/Templates/siteassistpro_template.dwt.php" codeOutsideHTMLIsLocked="false" -->undefined
interestingly, I could see the place holder text in Dreamweaver and IE8 but not in firefox.