title: xsd validation complains about missing attribute and wrong attribute at the same time
body: <p>I get somewhat schizophrenic behavior from xsd validation. This <a href="http://www.utilities-online.info/xsdvalidation/?save=e7e63665-5e0a-4387-9ecb-8dfa57d32fc5-xsdvalidation#.VVZHJXV7jUY" rel="nofollow">link</a> shows the xml and xsd + the errors in an online schema validator. When I run this locally with xmllint</p>
  
  <pre><code>xmllint --noout --nonet --schema devhelp2.xsd tester.devhelp2
  </code></pre>
  
  <p>I get similar warnings:</p>
  
  <pre><code>tester.devhelp2:5: element sub: Schemas validity error : Element '{urn:devhelp}sub', attribute 'name': The attribute 'name' is not allowed.
  tester.devhelp2:5: element sub: Schemas validity error : Element '{urn:devhelp}sub', attribute 'link': The attribute 'link' is not allowed.
  tester.devhelp2:5: element sub: Schemas validity error : Element '{urn:devhelp}sub': The attribute '{urn:devhelp}name' is required but missing.
  tester.devhelp2:5: element sub: Schemas validity error : Element '{urn:devhelp}sub': The attribute '{urn:devhelp}link' is required but missing.
  </code></pre>
  
  <p>but this has a hint that there is something wrong with the namespace.</p>
  
  <h1>PS:</h1>
  
  <p>I can make it validate by dropping the xmlns completely (as taken from <a href="http://zvon.org/xxl/XMLSchemaTutorial/Output/ser_attributeFormDefault_st2.html" rel="nofollow">zvon.org</a>). See <a href="http://www.utilities-online.info/xsdvalidation/?save=6ee6f445-2885-4696-864e-110210edba9d-xsdvalidation#.VVtRxnV7jUY" rel="nofollow">here for the new online validator example</a> - I'd still like to understand it though, isn't there a solution keeping the xmlns?</p>