More XPath

Hi,

I have a n XMLDocument containing the following XML:

<root>
 <r rn="90">
  <f1>WILMK</f1>
  <f2>Wilman%20Kala</f2>
 </r>
 <r rn="91">
  <f1>WOLZA</f1>
  <f2>Wolski%20%20Zajazd</f2>
 </r>
 <DSODetails>
  <LastErrorCode>0</LastErrorCode>
  <BOF>1</BOF>
  <EOF>1</EOF>
 </DSODetails>
</root>

When I exucute
var aItems = document.evaluate("//r", xNode, oNSResolver, 
XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);

Then aItem.length = 2

But when I execute
var aItems = document.evaluate("//DSODetails", xNode, oNSResolver, 
XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
Then aItem.length = 0

Is this a bug? It works fine if I lowercase all the tag names. The project I 
am working on is an ex IE project and going back to change all the XML tags 
to lower case is not an option. It will mean having to change thousand of 
client side scripts that generate XML.

Is there a work around for this problem?

Thanks,
Leon