Index: _source/plugins/selection/plugin.js
===================================================================
--- _source/plugins/selection/plugin.js	(revision 3457)
+++ _source/plugins/selection/plugin.js	(working copy)
@@ -323,6 +324,9 @@
 				this.isInvalid = true;
 			}
 		}
+		else 
+			// Validate the selection.
+			this.isInvalid = !this.getNative();
 	};
 
 	var styleObjectElements =