[MonoDevelop] Error when closing editor window

[monodevelop at vanhoecke.org]

Hi,

(Working on OSX with MonoDevelop 2.4)

When closing an editor window, I get following error:

System.NullReferenceException: Object reference not set to an instance 
of an object
   at 
MonoDevelop.SourceEditor.SourceEditorWidget+<OnParseInformationChanged>c__AnonStoreyD.<>m__46 
(System.Object , System.EventArgs ) [0x00000] in <filename unknown>:0
   at Gtk.Application+InvokeCB.Invoke () [0x00000] in <filename unknown>:0
   at GLib.Timeout+TimeoutProxy.Handler () [0x00000] in <filename 
unknown>:0


Is this a known problem?
How can I get a fix for it?

TIA,

Guido