Classpath issue with ANT calling a P4 task?

Have a ANT target calling another target, see code below
<target name="build-util.version-checkout" if="checkin-version">
      <ant antfile="${batch-home}\build-scc.xml" target="build-scc.checkout-file-${scc-provider}">
      <property name="source-file" value="${scc-java-tree}/version-${project}.properties"/>
      </ant>
</target>
which is giving the following error:
java.lang.NoClassDefFoundError: org/apache/oro/text/perl/Perl5Util
this error has only come up when I changed the target the code is calling as I had add a new classpath for ANT to work with P4 (perforce) see code snippetStart Free Trial

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<target name="build-scc.checkout-file-vss">
	<antcall target="build-scc.get-file-vss">
  	</antcall>
 <taskdef classname="org.apache.tools.ant.taskdefs.optional.perforce.P4Edit" name="P4edit">
    <classpath>
	<pathelement location="C:\apache-ant-1.6.2\lib\optional-1.5.4.jar"/>
	</classpath>
	</taskdef>
	<echo>Checkout: P4: checking out file $$/${source-file}</echo>
	<P4edit view="$$/${source-file}"/>
</target>