idL085 (Identity Constraint)

Hi,

Why the following test (i.e., idL085 - XPath Validation) on 
  http://www.w3.org/XML/2001/05/xmlschema-test-collection/result-ms-identityConstraint.htm

is expected to fail?

Can someone shed some lights on this?

Thx,

-Stanley

<?xml version="1.0" ?> 
- <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" targetNamespace="myNS.tempuri.org" xmlns:myNS="myNS.tempuri.org" xmlns="myNS.tempuri.org">
- <xs:element name="root">
- <xs:complexType>
- <xs:sequence>
  <xs:element ref="t" maxOccurs="unbounded" /> 
  </xs:sequence>
  </xs:complexType>
- <xs:key id="foo123" name="tableu">
  <xs:selector xpath=".//myNS:*" /> 
  <xs:field xpath="@col" /> 
  <xs:field xpath="myNS:row" /> 
  </xs:key>
  </xs:element>
  <xs:element name="t" type="ttype" /> 
- <xs:complexType name="ttype">
- <xs:sequence>
  <xs:element name="row" type="xs:string" /> 
  </xs:sequence>
  <xs:attribute name="col" type="xs:string" /> 
  </xs:complexType>
  </xs:schema>


<?xml version="1.0" ?> 
- <myNS:root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="myNS.tempuri.org idL085.xsd" xmlns:myNS="myNS.tempuri.org">
- <myNS:t col="1">
  <myNS:row>1</myNS:row> 
  </myNS:t>
- <myNS:t col="2">
  <myNS:row>2</myNS:row> 
  </myNS:t>
- <myNS:t col="2">
  <myNS:row>11</myNS:row> 
  </myNS:t>
  </myNS:root>