Here's the log:

[Info  23:32:42.599] Running Banshee 1.4.1
[Info  23:32:43.722] Querying MusicBrainz for Disc Release (Q0d.dY8xjPu0ZXZez2TCeJ1LwpI-)
[Info  23:32:44.045] All services are started 1,316798s
[Info  23:32:44.603] nereid Client Started
[Info  23:32:45.827] Query finished (success: True, 2,105041 seconds)
Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
GLib.GException: Chave ou diretório inválido: "/apps/banshee-1/nereid/track_view_columns/_audio_cd_source-cd_de_áudio/rip_enabled/order": "\303" não é um caractere ASCII, logo não é permitido em nomes de chave
  at GConf.Client.SetValue (System.String key, GConf.Value val) [0x00000] 
  at GConf.ClientBase.Set (System.String key, System.Object val) [0x00000] 
  at Banshee.GnomeBackend.GConfConfigurationClient.Set[Int32] (System.String namespace, System.String key, Int32 value) [0x00000] 
  at Banshee.Configuration.ConfigurationClient.Set[Int32] (System.String namespace, System.String key, Int32 value) [0x00000] 
  at Banshee.Collection.Gui.PersistentColumnController.Save (Hyena.Data.Gui.Column column, Int32 index) [0x00000] 
  at Banshee.Collection.Gui.PersistentColumnController.SaveCore () [0x00000] 
  at Banshee.Collection.Gui.PersistentColumnController.OnTimeout () [0x00000] 
  at GLib.Timeout+TimeoutProxy.Handler () [0x00000] 
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at GLib.Timeout+TimeoutProxy.Handler()
   at GLib.Timeout+TimeoutProxy.Handler()
   at Gtk.Application.gtk_main()
   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.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()

It looks like banshee is not properly handling the access of some gconf key with non-ascii characters.