crash during crop

placed crop mark around image, hit Enter, crash, has only happened once, other cropping has been fine

Software version: 0.8.1.1083
.NET runtime version: v2.0.50727
Time: 2011-05-11 08:47:29 +10:00
OS: Windows XP Professional Service Pack 3 x32 modus Version = 5.1.2600.196608
GDI object count: 94
User object count: 69
Exception: System.NullReferenceException
Message: Object reference not set to an instance of an object.

Stack:
at Greenshot.Drawing.DrawableContainerList.MoveBy(Int32 dx, Int32 dy)
at Greenshot.Drawing.Surface.ApplyCrop(Rectangle cropRectangle)
at Greenshot.Drawing.Surface.ConfirmSelectedConfirmableElements(Boolean confirm)
at Greenshot.Drawing.Surface.ProcessCmdKey(Keys k)
at Greenshot.ImageEditorForm.ProcessCmdKey(Message& msg, Keys k)
at System.Windows.Forms.Control.ProcessCmdKey(Message& msg, Keys keyData)
at System.Windows.Forms.ContainerControl.ProcessCmdKey(Message& msg, Keys keyData)
at System.Windows.Forms.Control.PreProcessMessage(Message& msg)
at System.Windows.Forms.Control.PreProcessControlMessageInternal(Control target, Message& msg)
at System.Windows.Forms.Application.ThreadContext.PreTranslateMessage(MSG& msg)