Attributes not populated when deserializing XML

I'm attempting to deserialize the following XML. It all seems to work OK, but the attributes of the resulting XmlObject subclass are not populated. I isolated the case into a unit test.Below are the:

• XML Message being parsed
• The code used to parse it
• Parts of the XSDs

A clue might be the fact that this is the first time I'm deserializing something that has a "choice" element....

=== XML Message being parsed ===
<makeOrderValueException
xmlns="http://java.sun.com/products/oss/xml/ServiceActivation"
xmlns:co="http://java.sun.com/products/oss/xml/Common"
xmlns:ri="http://www.ossj.org/RiServiceActivation"
xmlns:sa="http://java.sun.com/products/oss/xml/ServiceActivation"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.ossj.org/ServiceActivation">
<co:IllegalArgumentException>
<message>javax.oss.IllegalArgumentException: Order type non.existing.OrderValue ist not supported
javax.oss.IllegalArgumentException: Order type non.existing.OrderValue ist not supported
</message>
</co:IllegalArgumentException>
</makeOrderValueException>

=== The unit test code ===

ClassPathResource res = new ClassPathResource("illegalAttributeException.xml");

MakeOrderValueExceptionDocument exDoc = MakeOrderValueExceptionDocument.Factory.parse(res.getInputStream());
MakeOrderValueException move = exDoc.getMakeOrderValueException();

log.debug("testIllegalAttributeException() exDoc: " + move.xmlText()); // <- Shows correct XML

assertTrue(move.isSetIllegalArgumentException()); // <-- FAILS
assertNotNull(move.getIllegalArgumentException()); // <-- FAILS

=== XSD parts from "co" schema (http://java.sun.com/products/oss/xml/Common) ===

<complexType name="BaseException" abstract="true">
<annotation>
<documentation>a</documentation>
</annotation>
<sequence>
<element name="message" type="string">
<annotation>
<documentation>The Message element indicates the error message from the Exception. This is most
likely the results from a Exception.getMessage() call.</documentation>
</annotation>
</element>
</sequence>
</complexType>

<complexType name="IllegalArgumentException">
<annotation>
<documentation>The IllegalArgumentException exception is
returned by the OSS through Java XML/JMS interface to report
that the request could not be completed because one of the
arguments passed in is invalid.</documentation>
</annotation>
<complexContent>
<extension base="co:BaseException">
<sequence/>
</extension>
</complexContent>
</complexType>

<complexType name="RemoteException">
<annotation>
<documentation> The RemoteException is returned when an
errors occurs during any remote object
operation.</documentation>
</annotation>
<complexContent>
<extension base="co:BaseException">
<sequence/>
</extension>
</complexContent>
</complexType>

==== XSD parts from default schema (http://java.sun.com/products/oss/xml/ServiceActivation) ====

<element name="makeOrderValueException">
<annotation>
<documentation>This is returned if an exception
occurrs.</documentation>
</annotation>
<complexType>
<choice>
<element name="illegalArgumentException" type="co:IllegalArgumentException"/>
<element name="remoteException" type="co:RemoteException"/>
</choice>
</complexType>
</element>

==================