Issue when loading XML as a stream


I am trying to get an XML file using pub.xml.loadXMLNode service from an URL, in wM6.1. When I am try to load the XML as bytes, I get a valid XML and am able to convert to document. But when I load the the XML as stream, the XML is not loaded properly, and only partial download happens.
I am trying to use the loadXMLNode with the pub.xml.getXMLNodeIterator service and due to the performance reasons will like to go with XML as stream. I even tried converting the stream to node using the pub.xml.xmlStringToXMLNode service, but that didn’t help either.
If you have any idea what I might be doing wrong of there is something that I am missing, please let me know.