Index: dialin/hd/ui_proxy.py
===================================================================
diff -u -rcadb919bce9140638cae552306f374961833dafc -rcee26db30e61173225355e599e2f99d6ddd13808
--- dialin/hd/ui_proxy.py	(.../ui_proxy.py)	(revision cadb919bce9140638cae552306f374961833dafc)
+++ dialin/hd/ui_proxy.py	(.../ui_proxy.py)	(revision cee26db30e61173225355e599e2f99d6ddd13808)
@@ -507,7 +507,7 @@
         "hd_new_treatment_params_timestamp",
         "treatment_parameters"
     ])
-    def _handler_treatment_param_settings(self, message, timestamp):
+    def _handler_treatment_param_settings(self, message, timestamp=0.0):
         """
         Handler for UI msg containing user set treatment parameters.