Banshee Ubuntu One Music Store extension fails to load

Binary package hint: banshee

I just upgraded to Maverick and noticed that when I loaded Banshee the U1MS source didn't appear. I went into the preferences and unchecked/re-checked the option and Banshee crashed. I then started Banshee from the command line and have pasted the output below:

ssweeny[~]$ banshee
[Info 21:07:59.914] Running Banshee 1.7.3: [Ubuntu maverick (development branch) (linux-gnu, i686) @ 2010-08-06 16:24:30 UTC]
/home/ssweeny/.themes/Sonar-Dust/gtk-2.0/gtkrc:92: Murrine configuration option "gradients" is no longer supported and will be ignored.
/home/ssweeny/.themes/Sonar-Dust/gtk-2.0/gtkrc:163: Murrine configuration option "gradients" is no longer supported and will be ignored.
/home/ssweeny/.themes/Sonar-Dust/gtk-2.0/gtkrc:198: Murrine configuration option "gradients" is no longer supported and will be ignored.
/home/ssweeny/.themes/Sonar-Dust/gtk-2.0/gtkrc:205: Murrine configuration option "profile" is no longer supported and will be ignored.
/home/ssweeny/.themes/Sonar-Dust/gtk-2.0/gtkrc:558: Murrine configuration option "gradients" is no longer supported and will be ignored.
/home/ssweeny/.themes/Sonar-Dust/gtk-2.0/gtkrc:606: error: invalid string constant "spinbutton", expected valid string constant
[Info 21:08:00.343] Starting collection of anonymous usage data
[Info 21:08:01.305] Updating web proxy from GConf

(Banshee:1943): Gtk-WARNING **: Refusing to add non-unique action 'CloseAction' to action group 'Global'
[Info 21:08:01.492] All services are started 1.266668

** (Banshee:1943): WARNING **: The class UbuntuOne.U1MusicStore could not be loaded, used in ubuntuone-sharp, Version=1.0.0.0, Culture=neutral, PublicKeyToken=0738eb9f132ed756

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.TypeLoadException: A type load exception has occurred.
  at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (object,object[],System.Exception&)
  at System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  at System.Reflection.MonoCMethod.Invoke (BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  at System.Reflection.ConstructorInfo.Invoke (System.Object[] parameters) [0x00000] in <filename unknown>:0
  at System.Activator.CreateInstance (System.Type type, Boolean nonPublic) [0x00000] in <filename unknown>:0
  at System.Activator.CreateInstance (System.Type type) [0x00000] in <filename unknown>:0
  at Mono.Addins.TypeExtensionNode.CreateInstance () [0x00000] in <filename unknown>:0
  at Banshee.Sources.SourceManager.OnExtensionChanged (System.Object o, Mono.Addins.ExtensionNodeEventArgs args) [0x00000] in <filename unknown>:0
  at Mono.Addins.ExtensionNode.add_ExtensionNodeChanged (Mono.Addins.ExtensionNodeEventHandler value) [0x00000] in <filename unknown>:0
[Info 21:08:02.491] nereid Client Started

Additionally, below is the output when I uncheck/recheck the U1MS option (leading to the crash):
Marshaling toggled signal
Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.TypeLoadException: A type load exception has occurred.
  at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (object,object[],System.Exception&)
  at System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  at System.Reflection.MonoCMethod.Invoke (BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  at System.Reflection.ConstructorInfo.Invoke (System.Object[] parameters) [0x00000] in <filename unknown>:0
  at System.Activator.CreateInstance (System.Type type, Boolean nonPublic) [0x00000] in <filename unknown>:0
  at System.Activator.CreateInstance (System.Type type) [0x00000] in <filename unknown>:0
  at Mono.Addins.TypeExtensionNode.CreateInstance () [0x00000] in <filename unknown>:0
  at Banshee.Sources.SourceManager.OnExtensionChanged (System.Object o, Mono.Addins.ExtensionNodeEventArgs args) [0x00000] in <filename unknown>:0
  at Mono.Addins.ExtensionNode.OnChildNodeAdded (Mono.Addins.ExtensionNode node) [0x00000] in <filename unknown>:0
  at Mono.Addins.ExtensionNode.NotifyChildChanged () [0x00000] in <filename unknown>:0
  at Mono.Addins.TreeNode.NotifyChildrenChanged () [0x00000] in <filename unknown>:0
  at Mono.Addins.ExtensionTree.LoadExtensionElement (Mono.Addins.TreeNode tnode, System.String addin, Mono.Addins.Description.ExtensionNodeDescriptionCollection extension, System.Int32& curPos, Mono.Addins.BaseCondition parentCondition, Boolean inComplextCondition, System.Collections.ArrayList addedNodes) [0x00000] in <filename unknown>:0
  at Mono.Addins.ExtensionTree.LoadExtension (System.String addin, Mono.Addins.Description.Extension extension, System.Collections.ArrayList addedNodes) [0x00000] in <filename unknown>:0
  at Mono.Addins.ExtensionContext.LoadModuleExtensionNodes (Mono.Addins.Description.Extension extension, System.String addinId, Mono.Addins.Description.ExtensionNodeSet nset, System.Collections.ArrayList loadedNodes) [0x00000] in <filename unknown>:0
  at Mono.Addins.ExtensionContext.ActivateAddinExtensions (System.String id) [0x00000] in <filename unknown>:0
  at Mono.Addins.AddinSessionService.ActivateAddin (System.String id) [0x00000] in <filename unknown>:0
  at Mono.Addins.Database.AddinDatabase.EnableAddin (System.String domain, System.String id, Boolean exactVersionMatch) [0x00000] in <filename unknown>:0
  at Mono.Addins.Addin.set_Enabled (Boolean value) [0x00000] in <filename unknown>:0
  at Banshee.Addins.Gui.AddinView+<AddinView>c__AnonStorey6.<>m__5 (System.Object o, Gtk.ToggledArgs a) [0x00000] in <filename unknown>:0
  at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[],System.Exception&)
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0
  at System.Delegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0
  at System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0
  at System.Delegate.DynamicInvoke (System.Object[] args) [0x00000] in <filename unknown>:0
  at GLib.Signal.ClosureInvokedCB (System.Object o, GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0
  at GLib.SignalClosure.Invoke (GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0
  at GLib.SignalClosure.MarshalCallback (IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data) [0x00000] in <filename unknown>:0
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at GLib.SignalClosure.MarshalCallback(IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data)
   at Gtk.Dialog.gtk_dialog_run(IntPtr )
   at Gtk.Dialog.Run()
   at Banshee.Gui.Dialogs.BansheeDialog.Run()
   at Banshee.Gui.GlobalActions.OnPreferences(System.Object o, System.EventArgs args)
   at System.Reflection.MonoMethod.InternalInvoke(System.Object , System.Object[] , System.Exception ByRef )
   at System.Reflection.MonoMethod.Invoke(System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
   at System.Reflection.MethodBase.Invoke(System.Object obj, System.Object[] parameters)
   at System.Delegate.DynamicInvokeImpl(System.Object[] args)
   at System.MulticastDelegate.DynamicInvokeImpl(System.Object[] args)
   at System.Delegate.DynamicInvoke(System.Object[] args)
   at GLib.Signal.ClosureInvokedCB(System.Object o, GLib.ClosureInvokedArgs args)
   at GLib.SignalClosure.Invoke(GLib.ClosureInvokedArgs args)
   at GLib.SignalClosure.MarshalCallback(IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data)
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Banshee.Gui.GtkBaseClient.Run()
   at Banshee.Gui.GtkBaseClient.Startup()
   at Hyena.Gui.CleanRoomStartup.Startup(Hyena.Gui.StartupInvocationHandler startup)
   at Banshee.Gui.GtkBaseClient.Startup()
   at Banshee.Gui.GtkBaseClient.Startup(System.String[] args)
   at Nereid.Client.Main(System.String[] args)
   at System.AppDomain.ExecuteAssembly(System.Reflection.Assembly , System.String[] )
   at System.AppDomain.ExecuteAssemblyInternal(System.Reflection.Assembly a, System.String[] args)
   at System.AppDomain.ExecuteAssembly(System.String assemblyFile, System.Security.Policy.Evidence assemblySecurity, System.String[] args)
   at System.AppDomain.ExecuteAssembly(System.String assemblyFile)
   at Booter.Booter.BootClient(System.String clientName)
   at Booter.Booter.Main()

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: banshee 1.7.3-2ubuntu2
ProcVersionSignature: Ubuntu 2.6.35-17.23-generic 2.6.35.2
Uname: Linux 2.6.35-17-generic i686
Architecture: i386
Date: Mon Aug 23 21:12:20 2010
ExecutablePath: /usr/lib/banshee-1/Banshee.exe
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
InterpreterPath: /usr/bin/mono
ProcEnviron:
 SHELL=/bin/bash
 LANG=en_US.utf8
SourcePackage: banshee