Overloading not supported by extension interfaces feature?

Dear list,

I am using the extension interfaces feature documented at 
http://wiki.apache.org/xmlbeans/ExtensionInterfacesFeature, but I can't get 
it to handle overloaded methods. For example, if I have an interface that 
contains multiple methods with the same name but different signatures like 
this:

public interface MyInterface {

    public Integer myMethod ( Integer v );
    public Double  myMethod ( Double v );

}

with static handlers like this:

public class MyHandlers {

   public static Integer myMethod ( XmlObject xo, Integer v ) {
      ...
   }

   public static Double  myMethod ( XmlObject xo, Double v ) {
    ...
   }

}

I can't incorporate this into the XMLBeans api - I get an error something 
like this during the SchemaCompiler step:

/path/to/xmlbeans.xsdconfig:28:6: error: Return type for method 'Integer 
myMethod(XmlObject, Double)' does not match the return type of the interface 
method : 'Double'

I am using version 2.5.0 of XMLBeans.

The return types of the interface and handler methods have clearly become 
confused. Should this work? Am I doing something wrong? I haven't found a 
reference to this issue in the bug database. Shall I file one?

Regards,
Peter.

-- 
Peter Keller                                     Tel.: +44 (0)1223 353033
Global Phasing Ltd.,                             Fax.: +44 (0)1223 366889
Sheraton House,
Castle Park,
Cambridge CB3 0AX
United Kingdom