boolean requiredProperty used in archetype ressource doesn't work as expected

I created a custom Property like ${isCXF} to enable cxf-functionality in our archetype. In a resource file (web.xml) I've something like this:

#if($isCXF)
<!-- CXF SOAP servlet -->
<servlet>
[...]
#end

and this doesn't work. isCXF is always true! and the code in the if-block is always rendered consequently. So I modified it to: ($isCXF == true). And that worked, but it's more verbose and error-prone.

maybe the Object generated for the variable doesn't overwrite toString correctly?