Banshee won't start at all.  An exception is thrown.  Here is the output:

An unhandled exception was thrown: libbanshee

  at (wrapper managed-to-native) Banshee.GStreamer.PlayerEngine:bp_new ()
  at Banshee.GStreamer.PlayerEngine..ctor () [0x00000] 
  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] 
Exception has been thrown by the target of an invocation.

  at System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] 
  at System.Reflection.MonoCMethod.Invoke (BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] 
  at System.Reflection.ConstructorInfo.Invoke (System.Object[] parameters) [0x00000] 
  at System.Activator.CreateInstance (System.Type type, Boolean nonPublic) [0x00000] 
  at System.Activator.CreateInstance (System.Type type) [0x00000] 
  at Mono.Addins.TypeExtensionNode.CreateInstance () [0x00000] 
  at Mono.Addins.InstanceExtensionNode.CreateInstance (System.Type expectedType) [0x00000] 
  at Banshee.MediaEngine.PlayerEngineService.LoadEngine (Mono.Addins.TypeExtensionNode node) [0x00000] 
  at Banshee.MediaEngine.PlayerEngineService.Banshee.ServiceStack.IInitializeService.Initialize () [0x00000] 
  at Banshee.ServiceStack.ServiceManager.RegisterService (System.Type type) [0x00000] 
Exception has been thrown by the target of an invocation.

  at System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] 
  at System.Reflection.MonoCMethod.Invoke (BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] 
  at System.Reflection.ConstructorInfo.Invoke (System.Object[] parameters) [0x00000] 
  at System.Activator.CreateInstance (System.Type type, Boolean nonPublic) [0x00000] 
  at System.Activator.CreateInstance (System.Type type) [0x00000] 
  at Banshee.Gui.GtkBaseClient.Startup () [0x00000] 
  at Hyena.Gui.CleanRoomStartup.Startup (Hyena.Gui.StartupInvocationHandler startup) [0x00000] 

.NET Version: 2.0.50727.1433
OS Version: Unix 10.0.0.0

Assembly Version Information:

Banshee.GStreamer (1.5.0.0)
Mono.Media (1.5.0.0)
System.Core (3.5.0.0)
System.Transactions (2.0.0.0)
NDesk.DBus.GLib (1.0.0.0)
Mono.Cairo (2.0.0.0)
System.Data (2.0.0.0)
Mono.Data.Sqlite (1.5.0.0)
NDesk.DBus (1.0.0.0)
System.Xml (2.0.0.0)
gdk-sharp (2.12.0.0)
Mono.Addins (0.4.0.0)
atk-sharp (2.12.0.0)
glib-sharp (2.12.0.0)
Hyena.Gui (1.5.0.0)
Mono.Posix (2.0.0.0)
gtk-sharp (2.12.0.0)
Banshee.Core (1.5.0.0)
Hyena (1.5.0.0)
System (2.0.0.0)
Banshee.Services (1.5.0.0)
Banshee.ThickClient (1.5.0.0)
Nereid (1.5.0.0)
mscorlib (2.0.0.0)

Platform Information: 

Disribution Information: