I can omit ALL of the namespace registration in the code as is and it doesn't make a difference. It still works with all the prefix qualifiers in the findnode() method. If I try to remove the part of the line you mention in the xml... I didn't get far as it was requiring a great deal of editing the remaining xml and I didn't get past the errors.
Is it requiring all the prefix qualifiers in the call to findnode because the ss namespace is the same uri as the default namespace? I was expecting it to let me omit the ss prefix because of that. That's the heart of my confusion that I have to specify all those prefixes even where xml doesn't include the prefix.