Comment 1 for bug 623655

I see this too. With rhythmbox 0.13.0git20100819-0ubuntu1 and rhythmbox-ubuntuone-music-store 0.1.3-0ubuntu1 I can select the UbuntuOne Music store in Edit/Plugins, but it doesn't show up in the left pane. Starting rb from the command line I have (replacing potentially private stuff with '...'):

$ rhythmbox

(rhythmbox:5201): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed
** Message: pygobject_register_sinkfunc is deprecated (GstObject)

(rhythmbox:5201): Rhythmbox-WARNING **: Could not open device /dev/radio0
** Message: useQuirks: 0 / 0 /
Traceback (most recent call last):
  File "/usr/lib/rhythmbox/plugins/umusicstore/__init__.py", line 43, in activate
    self.music_store_widget.activate(shell)
  File "/usr/lib/rhythmbox/plugins/umusicstore/MusicStoreWidget.py", line 57, in activate
    self.entry_type = self.db.entry_register_type("U1EntryType")
AttributeError: '__main__.RhythmDBTree' object has no attribute 'entry_register_type'
Traceback (most recent call last):
  File "/usr/lib/rhythmbox/plugins/radio-browser/radio-browser.py", line 110, in activate
    entry_type = db.entry_register_type("RadioBrowserEntryType")
AttributeError: '__main__.RhythmDBTree' object has no attribute 'entry_register_type'
** Message: useQuirks: 0 / 0 /
** Message: useQuirks: 0 / 0 /
** Message: useQuirks: 0 / 0 /
** Message: useQuirks: 0 / 0 /
** Message: useQuirks: 0 / 0 /
** Message: useQuirks: 0 / 0 /
** Message: useQuirks: 0 / 0 /
** (rhythmbox:5201): DEBUG: Loading the real store page

liboauth: data to sign='GET&https%3A%2F%2Fone.ubuntu.com%2Fmusic%2Flogin&oauth_callback%3DNone%26oauth_consumer_key%3D...%26oauth_nonce%3...%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1282829831%26oauth_token%...%26oauth_verifier%3DNone%26oauth_version%3D1.0'

liboauth: key='...'

** Message: useQuirks: 0 / 0 / one.ubuntu.com
** (rhythmbox:5201): DEBUG: navigation requested to https://one.ubuntu.com/music/login?oauth_callback=None&oauth_consumer_key=...&oauth_nonce=...&oauth_signature_method=HMAC-SHA1&oauth_timestamp=1282829831&oauth_token=...&oauth_verifier=None&oauth_version=1.0&oauth_signature=...%3D
** Message: useQuirks: 0 / 0 / one.ubuntu.com
** Message: useQuirks: 0 / 0 / one.ubuntu.com
** Message: useQuirks: 0 / 0 / one.ubuntu.com
** (rhythmbox:5201): DEBUG: navigation requested to https://one.ubuntu.com/music/store-invalid-token
** (rhythmbox:5201): DEBUG: firing authentication
** (rhythmbox:5201): DEBUG: navigation requested to file:///usr/share/libubuntuone/1/javascript/load_error.html?https://one.ubuntu.com/music/store-invalid-token
** Message: useQuirks: 0 / 0 /
** (rhythmbox:5201): DEBUG: Got new credentials from ubuntu-sso

liboauth: data to sign='GET&https%3A%2F%2Fone.ubuntu.com%2Fmusic%2Flogin&oauth_callback%3DNone%26oauth_consumer_key%3...%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1282829832%26oauth_token%3...%3D1.0'

liboauth: key='...'

** Message: useQuirks: 0 / 0 / one.ubuntu.com
** (rhythmbox:5201): DEBUG: navigation requested to https://one.ubuntu.com/music/login?...

(rhythmbox:5201): GLib-CRITICAL **: g_str_has_prefix: assertion `str != NULL' failed
** Message: useQuirks: 0 / 0 / one.ubuntu.com
** Message: useQuirks: 0 / 0 / one.ubuntu.com
** (rhythmbox:5201): DEBUG: navigation requested to file:///usr/share/libubuntuone/1/javascript/connecting.html

(rhythmbox:5201): GLib-CRITICAL **: g_str_has_prefix: assertion `str != NULL' failed
** Message: useQuirks: 0 / 0 /