Please describe the problem:
I cannot get the --stop-when-finished flag to work. I tried the following to no avail:

banshee --stop-when-finished true
banshee --stop-when-finished 'true'
banshee --stop-when-finished 1
banshee --stop-when-finished

Steps to reproduce:
1. Open a terminal
2. Type the command banshee --stop-when-finished


Actual results:
There is a short pause of about 3 seconds, after which the following debug output is displayed.

banshee --stop-when-finished true

Unhandled Exception: System.ArgumentNullException: Cannot handle a null message; maybe the bus was disconnected
Parameter name: msg
  at NDesk.DBus.Connection.HandleMessage (NDesk.DBus.Message msg) [0x00000] 
  at NDesk.DBus.PendingCall.get_Reply () [0x00000] 
  at NDesk.DBus.Connection.SendWithReplyAndBlock (NDesk.DBus.Message msg) [0x00000] 
  at NDesk.DBus.BusObject.SendMethodCall (System.String iface, System.String member, System.String inSigStr, NDesk.DBus.MessageWriter writer, System.Type retType, System.Exception& exception) [0x00000] 
  at IPlaybackControllerServiceProxy.set_StopWhenFinished (Boolean ) [0x00000] 
  at Halie.Client.HandlePlayerCommands () [0x00000] 
  at Halie.Client.Main () [0x00000] 
  at (wrapper managed-to-native) System.AppDomain:ExecuteAssembly (System.Reflection.Assembly,string[])
  at System.AppDomain.ExecuteAssemblyInternal (System.Reflection.Assembly a, System.String[] args) [0x00000] 
  at System.AppDomain.ExecuteAssembly (System.String assemblyFile, System.Security.Policy.Evidence assemblySecurity, System.String[] args) [0x00000] 
  at (wrapper remoting-invoke-with-check) System.AppDomain:ExecuteAssembly (string,System.Security.Policy.Evidence,string[])
  at System.AppDomain.ExecuteAssembly (System.String assemblyFile) [0x00000] 
  at (wrapper remoting-invoke-with-check) System.AppDomain:ExecuteAssembly (string)
  at Booter.Booter.BootClient (System.String clientName) [0x00000] 
  at Booter.Booter.Main () [0x00000] 


Expected results:
Banshee should toggle the 'stop when finished' setting to 'true'. This error isn't just a warning, whereby the desired action would occur despite the debug error message; I checked in the GUI after issuing the command, the action fails entirely.

Does this happen every time?
Yes.

Other information: