Ok, so the forum won't let me post the xdoclet-build.xml file. Here it is:
*sigh* never mind. Before I had posted, I had tried re-running the Run XDoclet right-click menu choice several times with no luck (even trying to close and re-open the project, then Run XDoclet didn't work).
I went back into the XDoclet Configurations, checked all of the entries again, this time hit Apply, then OK, then Run XDoclet and it worked. WTF????