Hello, I'm having some trouble getting lxml (v. 2.2) to validate an ElementTree object that I'm building and was hoping someone on the list could help and maybe tell me what I'm doing wrong. If I create an ElementTree object directly from xml and an associated schema, it will validate fine. If I then construct a similar ElementTree object by just instantianting ElementTree, it will not validate. The odd thing is that the resulting xml from etree.tostring for both objects is identical. I've attached a python script that shows the problem I'm having. The validation error is: *** DocumentInvalid: Element 'Foo': No matching global declaration available for the validation root. I can get the second ElementTree object (etree2) to validate if I put the long explicit namesplace in front of the tag value (Foo) when I create etree2 in the script. So, if I change line 25 in the script to: rootelem = etree.Element('{http://example.com}Foo', {}, nsmap) , it will validate. However, the 2 resulting xml outputs are no longer equal b/c the output from etree2 is output with explict namespaces. Any ideas? Thanks for any help. -- James Slagle