Microsoft's .NET XMl Schema validator handles this situation by raising an exception.  Since this was not clearly defined in XSD 1.0, should this test not also accept an error?

      <description>
         Test that a namespaced attribute with a schema-defined default value is properly inserted into 
         the source document, with a namespace declaration if necessary. Note, the rules here are clearly 
         defined in XSD 1.1 (see 3.4.5.1 Attribute Default Value, namespace fixup). 
         But they are not clearly defined in XSD 1.0.
      </description>