skypetab-ng in kubuntu 12.04

:~$ skypetab
Missing method System.Type::op_Equality(Type,Type) in assembly /usr/lib/mono/2.0/mscorlib.dll, referenced in assembly /usr/lib/mono/gac/glib-sharp/2.12.0.0__35e10195dab3c99f/glib-sharp.dll

Unhandled Exception: System.MissingMethodException: Method not found: 'System.Type.op_Equality'.
  at GLib.Object.GetObject (IntPtr o, Boolean owned_ref) [0x00000] in <filename unknown>:0
  at GLib.Object.GetObject (IntPtr o) [0x00000] in <filename unknown>:0
  at Gdk.Display.get_Default () [0x00000] in <filename unknown>:0
  at SkypeTab.Globals.Main (System.String[] args) [0x00000] in <filename unknown>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.MissingMethodException: Method not found: 'System.Type.op_Equality'.
  at GLib.Object.GetObject (IntPtr o, Boolean owned_ref) [0x00000] in <filename unknown>:0
  at GLib.Object.GetObject (IntPtr o) [0x00000] in <filename unknown>:0
  at Gdk.Display.get_Default () [0x00000] in <filename unknown>:0
  at SkypeTab.Globals.Main (System.String[] args) [0x00000] in <filename unknown>:0