Audioscrobbler plugin doesn't upload when using proxy

this is the log when running banshee --debug:

carlos@carlos:~$ banshee --debug
** Running Mono with --debug **
[1 Info 10:55:44.886] Running Banshee 2.0.0: [Ubuntu 11.04 (linux-gnu, i686) @ 2011-06-28 05:46:57 UTC]
[1 Debug 10:55:45.031] Initializing GTK
[1 Debug 10:55:49.118] Post-Initializing GTK
[1 Debug 10:55:49.168] Configuration client extension loaded (Banshee.GnomeBackend.GConfConfigurationClient)
[1 Debug 10:55:49.184] Using default gconf-base-key
[1 Debug 10:55:49.246] Bus.Session.RequestName ('org.bansheeproject.Banshee') replied with PrimaryOwner
[1 Debug 10:55:49.361] Core service started (DBusServiceManager, 0,001451)
[1 Debug 10:55:49.364] Registering remote object /org/bansheeproject/Banshee/DBusCommandService (Banshee.ServiceStack.DBusCommandService) on org.bansheeproject.Banshee
[1 Debug 10:55:49.377] Core service started (DBusCommandService, 0,015622)
[1 Debug 10:55:49.833] Opened SQLite (version 3.7.4) connection to /home/carlos/.config/banshee-1/banshee.db
[1 Debug 10:55:49.833] Core service started (DbConnection, 0,456052)
[1 Debug 10:55:49.844] Database version 43 is up to date
[1 Debug 10:55:49.914] Core service started (PreferenceService, 0,044539)
[1 Debug 10:55:49.923] Core service started (Network, 0,008851)
[1 Debug 10:55:49.924] Registering remote object /org/bansheeproject/Banshee/SourceManager (Banshee.Sources.SourceManager) on org.bansheeproject.Banshee
[1 Debug 10:55:49.924] Core service started (SourceManager, 0,00086)
[1 Debug 10:55:49.936] Core service started (MediaProfileManager, 0,000376)
[1 Debug 10:55:49.939] Registering remote object /org/bansheeproject/Banshee/PlayerEngine (Banshee.MediaEngine.PlayerEngineService) on org.bansheeproject.Banshee
[1 Debug 10:55:49.942] Core service started (PlayerEngine, 0,006106)
[1 Debug 10:55:49.995] Registering remote object /org/bansheeproject/Banshee/PlaybackController (Banshee.PlaybackController.PlaybackControllerService) on org.bansheeproject.Banshee
[1 Debug 10:55:49.997] Core service started (PlaybackController, 0,003758)
[1 Debug 10:55:50.006] Starting - Startup Job
[1 Debug 10:55:50.007] Core service started (JobScheduler, 0,010565)
[1 Debug 10:55:50.025] IO provider extension loaded (Banshee.IO.Gio.Provider)
[1 Debug 10:55:50.154] Loaded HardwareManager backend: Banshee.Hardware.Gio
[1 Debug 10:55:50.156] Core service started (HardwareManager, 0,149013)
[1 Debug 10:55:50.159] Bus.Session.RequestName ('org.bansheeproject.CollectionIndexer') replied with PrimaryOwner
[1 Debug 10:55:50.161] Registering remote object /org/bansheeproject/Banshee/CollectionIndexerService (Banshee.Collection.Indexer.CollectionIndexerService) on org.bansheeproject.CollectionIndexer
[1 Debug 10:55:50.163] Core service started (CollectionIndexerService, 0,006713)
[1 Debug 10:55:50.165] Core service started (SaveTrackMetadataService, 0,002212)
[1 Debug 10:55:50.181] Adding icon theme search path: /usr/share/banshee/icons
[1 Debug 10:55:50.182] Core service started (GtkElementsService, 0,016709)
[1 Debug 10:55:50.185] Core service started (InterfaceActionService, 0,002205)
[1 Debug 10:55:50.356] Extension actions loaded: MetadataFixActions
[1 Debug 10:55:50.356] Registering remote object /org/bansheeproject/Banshee/GlobalUIActions (Banshee.Gui.GlobalActions) on org.bansheeproject.Banshee
[1 Debug 10:55:50.357] Album artwork path set to /home/carlos/.cache/media-art
[1 Debug 10:55:50.422] Core service started (ArtworkManager, 0,065848)
[1 Debug 10:55:50.422] Core service started (BookmarksService, 0,000246)
[1 Debug 10:55:50.943] Adding context page lastfm-recommendations
[1 Debug 10:55:51.016] Adding context page wikipedia
[1 Debug 10:55:52.695] Constructed Nereid interface: 2,194397
[1 Debug 10:55:53.095] Creating new surface cache for 90px images, capped at 0,62 MiB (20 items)
[1 Debug 10:55:53.291] Registering remote object /org/bansheeproject/Banshee/ClientWindow (Nereid.PlayerInterface) on org.bansheeproject.Banshee
[1 Debug 10:55:53.291] Core service started (NereidPlayerInterface, 2,826093)
[1 Debug 10:55:53.703] Extension service started (GStreamerCoreService, 0,410825)
[1 Debug 10:55:53.711] Extension service started (BpmService, 0,008207)
[1 Debug 10:55:53.717] Using GNOME 2.22 API for Multimedia Keys
[1 Debug 10:55:53.717] Extension service started (MultimediaKeysService, 0,006033)
[1 Debug 10:55:53.852] Audioscrobbler state: connected
[1 Debug 10:55:53.854] Extension service started (AudioscrobblerService, 0,136747)
[1 Debug 10:55:53.862] Extension service started (PodcastService, 0,007646)
[1 Debug 10:55:53.864] Extension service started (DapService, 0,0018)
[1 Debug 10:55:53.875] Extension service started (MprisService, 0,011075)
[1 Debug 10:55:53.877] Extension service started (DaapService, 0,0015)
[1 Info 10:55:53.883] Updating web proxy from GConf
[1 Debug 10:55:53.894] Manual proxy connection - http://192.168.1.92:8118/
[1 Debug 10:55:53.922] Extension service started (GnomeService, 0,045626)
[1 Debug 10:55:53.956] Extension service started (LastfmFingerprintService, 0,033871)
[1 Debug 10:55:53.960] Extension service started (AmazonMp3DownloaderService, 0,003167)
[1 Debug 10:55:53.963] Extension service started (CoverArtService, 0,003511)
[1 Debug 10:55:54.042] Extension service started (AudioCdService, 0,07913)
[1 Info 10:55:54.043] All services are started 4,79581
[1 Debug 10:55:54.661] Creating Pango.Layout, configuring Cairo.Context
[1 Debug 10:55:55.311] Registering remote object /org/bansheeproject/Banshee/SourceManager/PlayQueue (Banshee.PlayQueue.PlayQueueSource) on org.bansheeproject.Banshee
[1 Debug 10:55:55.311] Extension source loaded: Cola de reproducción
[1 Debug 10:55:55.334] Extension source loaded: Last.fm
[1 Debug 10:55:55.343] Extension source loaded: En reproducción
[1 Debug 10:55:55.365] Extension source loaded: Radio
[1 Debug 10:55:55.450] Extension source loaded: Cola del sistema de archivos
[1 Debug 10:55:55.461] Extension source loaded: Tienda de Amazon MP3
** (Banshee:16776): DEBUG: SyncDaemon already running, initializing SyncdaemonDaemon object

(Banshee:16776): libsoup-WARNING **: No feature manager for feature of type 'U1RequestChrome'

** (Banshee:16776): WARNING **: Error calling get_info: Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.7/dbus/service.py", line 702, in _message_cb
    retval = candidate_method(self, *args, **keywords)
  File "/usr/lib/pymodules/python2.7/ubuntuone-client/ubuntuone/platform/linux/dbus_interface.py", line 992, in get_info
    return self.syncdaemon_folders.get_info(path)
  File "/usr/lib/pymodules/python2.7/ubuntuone-client/ubuntuone/syncdaemon/interaction_interfaces.py", line 634, in get_info
    mdobj = self.fs.get_by_path(path.encode('utf-8'))
  File "/usr/lib/pymodules/python2.7/ubuntuone-client/ubuntuone/syncdaemon/filesystem_manager.py", line 773, in get_by_path
    mdid = self._idx_path[path]
KeyError: '/home/carlos/.ubuntuone/Purchased from Ubuntu One'

** (Banshee:16776): CRITICAL **: syncdaemon_folder_info_get_subscribed: assertion `SYNCDAEMON_IS_FOLDER_INFO (finfo)' failed
[1 Debug 10:55:59.118] Extension source loaded: Tienda de música de Ubuntu One
[1 Debug 10:55:59.132] Extension source loaded: Miro Guide
[1 Debug 10:55:59.154] Extension source loaded: Internet Archive
[1 Debug 10:55:59.186] Extension source loaded: Audiolibros
[1 Debug 10:55:59.193] Starting GTK main loop
[1 Debug 10:55:59.573] Growing surface cache for 90px images to 1,02 MiB (33 items)
[1 Debug 10:56:00.016] Creating Pango.Layout, configuring Cairo.Context
[1 Debug 10:56:00.196] Creating Pango.Layout, configuring Cairo.Context
[1 Warn 10:56:00.377] Forcefully breaking out of RCS loop b/c change in total_width less than 1.0
** (Banshee:16776): DEBUG: Loading the real store page

** (Banshee:16776): WARNING **: Got less number of items in credentials hash table than expected!
[1 Info 10:56:02.584] nereid Client Started
[1 Debug 10:56:02.589] Delayed Initializating Banshee.MediaEngine.PlayerEngineService
[1 Debug 10:56:02.610] (libbanshee:player) Stream volume supported: YES
[1 Debug 10:56:02.679] (libbanshee:player) Audiosink has volume: NO
[1 Debug 10:56:02.754] (libbanshee:player) Using system (gst-plugins-good) equalizer element
[1 Debug 10:56:02.835] Player state change: NotReady -> Ready
[1 Debug 10:56:02.839] Loaded equalizer presets: 0,000276
[1 Debug 10:56:02.844] Selected equalizer: Rock suave
[1 Debug 10:56:02.850] Player state change: Ready -> Idle
[1 Debug 10:56:02.858] (libbanshee:player) Disabled ReplayGain
[1 Info 10:56:02.860] GStreamer version 0.10.32.0, gapless: True, replaygain: False
[1 Debug 10:56:02.866] Delayed Initializating Banshee.Podcasting.PodcastService
[1 Debug 10:56:03.011] Delayed Initializating Banshee.Dap.DapService
[1 Debug 10:56:03.022] Dap support extension loaded: Banshee.Dap.MassStorage
[1 Debug 10:56:03.024] Dap support extension loaded: Banshee.Dap.AppleDevice
[1 Debug 10:56:03.026] Dap support extension loaded: Banshee.Dap.Mtp
[1 Debug 10:56:03.033] Delayed Initializating Banshee.Daap.DaapService
[2 Debug 10:56:03.124] Refreshing any podcasts that haven't been updated in over an hour
[3 Debug 10:56:04.022] DAAP Proxy listening for connections on port 8089
[1 Debug 10:56:04.122] Finished - Startup Job
[1 Debug 10:56:04.125] Starting - Descargando portadas
[4 Debug 10:56:04.131] Finished - Descargando portadas
[1 Warn 10:56:08.790] Forcefully breaking out of RCS loop b/c change in total_width less than 1.0
[1 Debug 10:56:16.256] Player state change: Idle -> Loading
[1 Debug 10:56:16.406] Player state change: Loading -> Loaded
[1 Debug 10:56:16.430] (libbanshee:player) [gapless] Triggering track-change signal
[1 Info 10:56:16.527] Uncached artwork size 223 requested
[1 Info 10:56:16.613] Uncached artwork size 39 requested
[1 Debug 10:56:16.616] Player state change: Loaded -> Playing
[1 Debug 10:56:16.676] Creating Pango.Layout, configuring Cairo.Context
[1 Debug 10:56:16.677] Creating Pango.Layout, configuring Cairo.Context
[1 Debug 10:56:17.749] TrackInfoDisplay RenderAnimation: 7,00 FPS
[1 Debug 10:56:17.750] TrackInfoDisplay RenderAnimation: 6,00 FPS
[5 Debug 10:56:33.324] Audioscrobbler sign-on succeeded - Session ID received
[5 Warn 10:56:44.318] Failed to get the response: System.Net.WebException: The remote server returned an error: (502) Server dropped connection.
  at System.Net.HttpWebRequest.CheckFinalStatus (System.Net.WebAsyncResult result) [0x00000] in <filename unknown>:0
  at System.Net.HttpWebRequest.SetResponseData (System.Net.WebConnectionData data) [0x00000] in <filename unknown>:0
[1 Debug 10:57:54.858] U1MS: Url Loaded: - http://stores.7digital.com/default.aspx?shop=496&partner=983
[5 Warn 10:58:44.329] Failed to get the response: System.Net.WebException: Error getting response stream (ReadDone2): ReceiveFailure ---> System.Exception: at System.Net.WebConnection.HandleError(WebExceptionStatus st, System.Exception e, System.String where)
   at System.Net.WebConnection.ReadDone(IAsyncResult result)
   at System.Net.Sockets.Socket+SocketAsyncResult.Complete()
   at System.Net.Sockets.Socket+Worker.Receive()
  at System.Net.WebConnection.HandleError (WebExceptionStatus st, System.Exception e, System.String where) [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Net.HttpWebRequest.EndGetResponse (IAsyncResult asyncResult) [0x00000] in <filename unknown>:0
  at Lastfm.AudioscrobblerConnection.TransmitGetResponse (IAsyncResult ar) [0x00000] in /build/buildd/banshee-2.0.0/src/Libraries/Lastfm/Lastfm/AudioscrobblerConnection.cs:308
^A^E[5 Debug 10:59:55.005] Submitted NowPlaying track to Audioscrobbler
[1 Debug 11:06:03.126] Refreshing any podcasts that haven't been updated in over an hour
[6 Debug 11:08:20.615] (libbanshee:player) [Gapless] Requesting next track
[1 Debug 11:08:21.173] Querying model for track to play in off:Next mode
[1 Debug 11:08:22.695] (libbanshee:player) [gapless] Triggering track-change signal
[1 Debug 11:08:22.702] Track Mouth Of The Architect - A Vivid Chaos (on Time & Withering) <00:12:06.9150000> [file:///home/carlos/M%C3%BAsica/Mouth%20of%20the%20Architect%20-%20Time%20&%20Withering/01%20-%20A%20Vivid%20Chaos.mp3] had playtime of 725938 msec (725sec), duration 726915 msec, queued: False
[1 Debug 11:08:22.705] OnEventChanged called with StartOfStream. Replacing current_track with pending_track: "Soil To Stone"
[1 Debug 11:08:23.721] TrackInfoDisplay RenderAnimation: 10,00 FPS
[1 Debug 11:08:23.721] TrackInfoDisplay RenderAnimation: 10,00 FPS
[7 Warn 11:08:31.721] Audioscrobbler upload failed - The request timed out and was aborted
[7 Warn 11:08:31.725] Failed to get the request stream - System.Net.WebException: Aborted. (in `System')
  at System.Net.HttpWebRequest.EndGetRequestStream (IAsyncResult asyncResult) [0x00000] in <filename unknown>:0
  at Lastfm.AudioscrobblerConnection.TransmitGetRequestStream (IAsyncResult ar) [0x00000] in /build/buildd/banshee-2.0.0/src/Libraries/Lastfm/Lastfm/AudioscrobblerConnection.cs:279
[8 Warn 11:09:37.727] Audioscrobbler upload failed - The request timed out and was aborted
[8 Warn 11:09:37.728] Failed to get the request stream - System.Net.WebException: Aborted. (in `System')
  at System.Net.HttpWebRequest.EndGetRequestStream (IAsyncResult asyncResult) [0x00000] in <filename unknown>:0
  at Lastfm.AudioscrobblerConnection.TransmitGetRequestStream (IAsyncResult ar) [0x00000] in /build/buildd/banshee-2.0.0/src/Libraries/Lastfm/Lastfm/AudioscrobblerConnection.cs:279
[9 Warn 11:10:43.733] Audioscrobbler upload failed - The request timed out and was aborted
[9 Warn 11:10:43.733] Failed to get the request stream - System.Net.WebException: Aborted. (in `System')
  at System.Net.HttpWebRequest.EndGetRequestStream (IAsyncResult asyncResult) [0x00000] in <filename unknown>:0
  at Lastfm.AudioscrobblerConnection.TransmitGetRequestStream (IAsyncResult ar) [0x00000] in /build/buildd/banshee-2.0.0/src/Libraries/Lastfm/Lastfm/AudioscrobblerConnection.cs:279
[10 Debug 11:11:48.339] Audioscrobbler sign-on succeeded - Session ID received
[5 Warn 11:11:57.346] Audioscrobbler upload failed - Plugin bug: Not all request variables are set - no POST parameters.
[11 Warn 11:12:13.741] Audioscrobbler upload failed - The request timed out and was aborted
[11 Warn 11:12:13.741] Failed to get the request stream - System.Net.WebException: Aborted. (in `System')
  at System.Net.HttpWebRequest.EndGetRequestStream (IAsyncResult asyncResult) [0x00000] in <filename unknown>:0
  at Lastfm.AudioscrobblerConnection.TransmitGetRequestStream (IAsyncResult ar) [0x00000] in /build/buildd/banshee-2.0.0/src/Libraries/Lastfm/Lastfm/AudioscrobblerConnection.cs:279

Description: Ubuntu 11.04
Release: 11.04
banshee:
  Instalados: 2.0.0-2ubuntu2
  Candidato: 2.0.0-2ubuntu2
  Tabla de versión:
 *** 2.0.0-2ubuntu2 0
        500 http://py.archive.ubuntu.com/ubuntu/ natty-updates/main i386 Packages
        100 /var/lib/dpkg/status
     2.0.0-2ubuntu1 0
        500 http://py.archive.ubuntu.com/ubuntu/ natty/main i386 Packages
I expect to upload information about music played to last.fm
In the debug shows that the plugin fails and something like "not all request variables are set"