Online validator problem - empty values accepted

Hi, I have tried to use the online schema validator:

   http://www.w3.org/2001/03/webdata/xsv

I am trying to validate an instance document.  In the "Address(es):"
input area, I have entered two URLs, separated by a space:

  http://sirius-software.com/daveweb/resources/schtst02.xml
  http://sirius-software.com/daveweb/resources/schtst02.xsd

I think that this instance document should fail, because all of
its attribute values, which are "the null string", are of types
which should not admit the missing value/null string.  However,
validation seems to succeed.  I have enclosed the instance and
schema documents below.  Can you please let me know whether
validation should succeed or fail on these?

Thank you.  Dave Evans, Sirius Software Inc., Cambridge MA USA
617-876-6677 ext. 204
------------
  <t
   boolean=""
   duration=""
   gYearMonth=""
   gYear=""
   gMonthDay=""
   gDay=""
   gMonth=""
   language=""
   NMTOKENS=""
   IDREFS=""
   ENTITIES=""
  />
------------
  <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="t">
    <xs:complexType>
      <xs:attribute name="boolean" type="xs:boolean"/>
      <xs:attribute name="duration" type="xs:duration"/>
      <xs:attribute name="gYearMonth" type="xs:gYearMonth"/>
      <xs:attribute name="gYear" type="xs:gYear"/>
      <xs:attribute name="gMonthDay" type="xs:gMonthDay"/>
      <xs:attribute name="gDay" type="xs:gDay"/>
      <xs:attribute name="gMonth" type="xs:gMonth"/>
      <xs:attribute name="NOTATION" type="xs:NOTATION"/>
      <xs:attribute name="language" type="xs:language"/>
      <xs:attribute name="NMTOKENS" type="xs:NMTOKENS"/>
      <xs:attribute name="IDREFS" type="xs:IDREFS"/>
      <xs:attribute name="ENTITIES" type="xs:ENTITIES"/>
    </xs:complexType>
  </xs:element>
  </xs:schema>
------------