jME Physics-2 javadoc build fails in netbeans 5.5.1 on OS X

Can anyone help me out with this?  I can get jME to build and everything (no errors anywhere) but not Physics… I can run a Clean and Build as described in the "getting started" section but javadoc generation fails.

This is from the console:

Created dir: /Users/ajp/jme/jME-Physics_2/dist/javadoc
Warning: Leaving out empty argument '-windowtitle'
/Users/ajp/jme/jME-Physics_2/nbproject/build-impl.xml:407: No source files and no packages have been specified.
BUILD FAILED (total time: 0 seconds)

This is the section to which the error message is linked:

        <javadoc destdir="${dist.javadoc.dir}" source="${javac.source}" notree="${javadoc.notree}" use="${javadoc.use}" nonavbar="${javadoc.nonavbar}" noindex="${javadoc.noindex}" splitindex="${javadoc.splitindex}" author="${}" version="${javadoc.version}" windowtitle="${javadoc.windowtitle}" private="${javadoc.private}" additionalparam="${javadoc.additionalparam}" failonerror="true" useexternalfile="true">
                <path path="${javac.classpath}"/>
                <pathelement location="${src.dir}"/>
            <packageset dir="${src.dir}" includes="*/**"/>
            <fileset dir="${src.dir}" includes="*.java"/>

Thanks all for any help,