Element names that begin with numbers are not valid XML. This is a handy tool for validating any XML you're trying to parse:
http://www.w3schools.com/xml/xml_validator.aspOne workaround would be to just prepend some static string to each hash when generating the XML.
Or, arguably, the more correct approach would be to not use the hash as an element name at all, but to do something like <item id="hash_value">