OK, my last note about this. The videoalpha code right below this expects value to be a string. In fact, a boolean value of False causes nothing to be written out:

     for key, value in attrs.items():
            # Mild workaround to ensure that tests pass -- if a field
            # is set to its default value, we don't need to write it out.
            if key in fields and fields[key].default == getattr(self, key):
                continue
            if value:      <------------------------------------ will not work with boolean value of False for value
                xml.set(key, unicode(value))

I'm not particularly sold on what is going on in this method, but I am inclined to leave it alone for now.