diff -up starcal2-2.0.0/scal2/ui_gtk/event/rules/common.py.compilefix starcal2-2.0.0/scal2/ui_gtk/event/rules/common.py
--- starcal2-2.0.0/scal2/ui_gtk/event/rules/common.py.compilefix	2012-07-18 21:32:32.000000000 +0430
+++ starcal2-2.0.0/scal2/ui_gtk/event/rules/common.py	2012-07-21 22:51:24.557960014 +0430
@@ -27,6 +27,7 @@ class MultiValueRule(gtk.HBox):
         self.removeButton.hide()## FIXME
 
     def removeLastWidget(self, obj=None):
+        return
 
     def addWidget(self, obj=None):
         widget = self.ValueWidgetClass()