I have done the following script. But it does not convert the namespaces for the xml elements with no value in it.
var xml = new XML(string);
The value present in string is "<level_1 xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/>"
When it is converted to xml, the value becomes "<level_1 xsi:nil="true"/>"
Can you post more of the script?
Are you getting the XML file from disk, or a string?