Ant 1.5.3 and XDoclet 1.2

[Jack J. Jackson]

I'm having a strange problem with XDoclet. The error message I get is:
taskdef class xdoclet.modules.hibernate.HibernateDocletTask cannot be found
So, I set up a little debugging target to see what's up. To eliminate as many variables as possible, I simplified the classpath to just the XDoclet JAR. I also did a search for another file in the JAR, HibernateSubTask for validation. Here's the target:

<target name="debug">
  <path id="test">
    <fileset dir="D:/swdev/java/xdoclet/1.2/lib">
      <include name="xdoclet-hibernate*.jar"/>
    </fileset>
  </path>

  <property name="cp" refid="test" />
  <echo message="classpath: ${cp}" />

  <echo message="Searching for xdoclet.modules.hibernate.HibernateDocletTask..." />
  <available classname="xdoclet.modules.hibernate.HibernateDocletTask" 
      property="x" classpathref="test" value="found!" />
  <echo message="findHibernateDocletTask = ${x}" />

  <echo message="Searching for xdoclet.modules.hibernate.HibernateSubTask..." />
  <available classname="xdoclet.modules.hibernate.HibernateSubTask" 
    property="y" classpathref="test" value="found!" />
  <echo message="findHibernateSubTask = ${y}" />
</target>

Here's the output:

debug:
  [echo] classpath: D:\swdev\java\xdoclet\1.2\lib\xdoclet-hibernate-module-1.2.jar
  [echo] Searching for xdoclet.modules.hibernate.HibernateDocletTask...
  [echo] findHibernateDocletTask = ${x}
  [echo] Searching for xdoclet.modules.hibernate.HibernateSubTask...
  [echo] findHibernateSubTask = found!

Clearly, HibernateDocletTask is not being found when the other class file is, though a check of the JAR file shows both class files are present.
I've checked and double-checked, but am stumped why the class isn't being found. At this point, I have to assume I'm overlooking something obvious.
Any ideas?