Index: CKEditor/trunk/_source/plugins/dialog/plugin.js
===================================================================
--- CKEditor/trunk/_source/plugins/dialog/plugin.js	(revision 6323)
+++ CKEditor/trunk/_source/plugins/dialog/plugin.js	(revision 6325)
@@ -1935,9 +1935,12 @@
 					});
 
-			do
-			{
-				var dialogPos = cursor.getPosition();
-				cursor.move( dialogPos.x, dialogPos.y );
-			} while ( ( cursor = cursor._.parentDialog ) );
+			if ( cursor )
+			{
+				do
+				{
+					var dialogPos = cursor.getPosition();
+					cursor.move( dialogPos.x, dialogPos.y );
+				} while ( ( cursor = cursor._.parentDialog ) );
+			}
 		};