Rhythmbox Magnatune catalogue doesn't load

Rhythmbox worked me fine for months, but now if I want to listen to some Music from Magnatune and click on the Magnatune icon, nothing happens. The catalogue doesn't load. After a while I can click on the play button, and the music starts but I can't see the catalogue so I can't choose the music I want to listen to. (I can only see the Magnatune logo)
On the other side Jamendo works me fine.

An error message:

Traceback (most recent call last):
  File "/usr/lib/rhythmbox/plugins/magnatune/MagnatuneSource.py", line 318, in __load_catalogue_read_cb
    parser.feed(data)
  File "/usr/lib/python2.5/xml/sax/expatreader.py", line 211, in feed
    self._err_handler.fatalError(exc)
  File "/usr/lib/python2.5/xml/sax/handler.py", line 38, in fatalError
    raise exception
xml.sax._exceptions.SAXParseException: <unknown>:1658:24: not well-formed (invalid token)