diff -r 72a826dfcfbb -r 02fe382c4511 graphics/LD_Objects.py
--- a/graphics/LD_Objects.py	Wed Jul 31 10:45:07 2013 +0900
+++ b/graphics/LD_Objects.py	Mon Nov 18 12:12:31 2013 +0900
@@ -774,8 +774,8 @@
     
     # Unconnect input and output
     def Clean(self):
-        self.Input.UnConnect()
-        self.Output.UnConnect()
+        self.Input.UnConnect(delete = self.Parent.GetDrawingMode() == FREEDRAWING_MODE)
+        self.Output.UnConnect(delete = self.Parent.GetDrawingMode() == FREEDRAWING_MODE)
                 
     # Refresh the size of text for name
     def RefreshNameSize(self):