Possible problem with JAXB marshalling

[qzpmwo qzpmwo]

Hi,

I'm having a strange problem with CXF RESTful service marsahlling base and
derived xsd types.

XSD:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema";
    xmlns:jaxb="http://java.sun.com/xml/ns/jaxb";
    xmlns="http://www.cisco.com/dms/xml/ns/dsmCommonService";
    targetNamespace="http://www.cisco.com/dms/xml/ns/dsmCommonService";
    elementFormDefault="unqualified" jaxb:version="2.0">

   <xs:complexType name="BaseType">
      <xs:sequence>
      </xs:sequence>
   </xs:complexType>

   <xs:complexType name="DerivedType">
      <xs:complexContent>
         <xs:extension base="BaseType">
            <xs:sequence>
            </xs:sequence>
         </xs:extension>
     </xs:complexContent>
   </xs:complexType>

   <xs:complexType name="ListType">
      <xs:sequence>
               <xs:element name="item" type="BaseType" minOccurs="0"
maxOccurs="unbounded" />
      </xs:sequence>
   </xs:complexType>

   <xs:element name="base" type="BaseType" />
   <xs:element name="derived" type="DerivedType" />
   <xs:element name="list" type="ListType" />

</xs:schema>

xjc has been used to jenerate java code from xsd. After that:

1)  @XmlSeeAlso pointing to DerivedType class and @XmlRootElement
annotations have been added to BaseType java class code
2) @XmlRootElement has been added to DerivedType java class code
3) @XmlRootElement has been added to ListType java class code

When my CXF rest service returns list of the Derived objects it produces xml
correctly:

<list>
    <base xsi:type="DerivedType">...</base>
    ...
    <base xsi:type="DerivedType">...</base>
</list>

But when I'm requesting 1 instance of the Derived object XML is wrong (as I
understand)

<derived>...</derived>

Since I did not specify substitution group in my opinion xml should be like
in list:

<base xsi:type="DerivedType">...</base>

Could you please clarify the issue for me and may be help me to solve this
problem.

Forgot to mention that I'm using CXF 2.2

Thanks in advance
--- Karen