Any wildcard and the .NET validator?

Does anyone here have information on the .NET XML Schema validator and 
their position on lax validation of wildcards?

i.e.:

  <complexType name="DescriptionType" mixed="true">
    <sequence>
      <any minOccurs="0" maxOccurs="unbounded"
        namespace="http://www.w3.org/1999/xhtml" processContents="lax"/>
    </sequence>
  </complexType>

    <description xmlns:html="http://www.w3.org/1999/xhtml">Blah 
Blah<html:em>blah</html:em>.<html:br/>Blah<html:strong>blah</html:strong> 
blah!</description>

Works in everything except the .NET tools (even MSXML passes the 
document...).

Thanks,
Jeff