exiting a screen leads to a black screen (1 Viewer)

[carmenm]

For a few day now(probably after a svn installation), whenever i exit a screen with ESC i get a black screen and this error in the log:

2009-09-17 20:03:49.880000 [ERROR][MPMain]: Exception   :System.NullReferenceException: Object reference not set to an instance of an object.
   at MediaPortal.GUI.Library.GUIWindowManager.UnRoute()
   at MediaPortal.GUI.Library.GUIWindowManager.ShowPreviousWindow()
   at WindowPlugins.GUITVSeries.TVSeriesPlugin.OnAction(Action action)
   at MediaPortal.GUI.Library.GUIWindowManager.OnAction(Action action)
   at MediaPortalApp.OnAction(Action action)
2009-09-17 20:03:49.880000 [ERROR][MPMain]: Exception   :Object reference not set to an instance of an object.
2009-09-17 20:03:49.880000 [ERROR][MPMain]:   site      :Void UnRoute()
2009-09-17 20:03:49.881000 [ERROR][MPMain]:   source    :Core
2009-09-17 20:03:49.881000 [ERROR][MPMain]:   stacktrace:   at MediaPortal.GUI.Library.GUIWindowManager.UnRoute()
   at MediaPortal.GUI.Library.GUIWindowManager.ShowPreviousWindow()
   at WindowPlugins.GUITVSeries.TVSeriesPlugin.OnAction(Action action)
   at MediaPortal.GUI.Library.GUIWindowManager.OnAction(Action action)
   at MediaPortalApp.OnAction(Action action)
2009-09-17 20:03:49.881000 [ERROR][MPMain]:   exception: Object reference not set to an instance of an object. Core    at MediaPortal.GUI.Library.GUIWindowManager.UnRoute()
   at MediaPortal.GUI.Library.GUIWindowManager.ShowPreviousWindow()
   at WindowPlugins.GUITVSeries.TVSeriesPlugin.OnAction(Action action)
   at MediaPortal.GUI.Library.GUIWindowManager.OnAction(Action action)
   at MediaPortalApp.OnAction(Action action)
2009-09-17 20:03:49.882000 [ERROR][MPMain]: Exception   :System.Exception: exception occured ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at MediaPortal.GUI.Library.GUIWindowManager.UnRoute()
   at MediaPortal.GUI.Library.GUIWindowManager.ShowPreviousWindow()
   at WindowPlugins.GUITVSeries.TVSeriesPlugin.OnAction(Action action)
   at MediaPortal.GUI.Library.GUIWindowManager.OnAction(Action action)
   at MediaPortalApp.OnAction(Action action)

It happens whatever screen i am on, plugins or weather, music ....
It happens with any skin except for blue3 and blue3Wide.
So i suppose there is a necessary change in the skins?
Can anyone comfirm
Is there an easy way to correct that locally?

Thanks