--- a/src/csma/examples/csma-multicast.cc	Mon Aug 13 10:46:09 2012 -0700
+++ b/src/csma/examples/csma-multicast.cc	Mon Aug 13 16:08:13 2012 -0700
@@ -134,8 +134,8 @@
   // every few seconds
   OnOffHelper onoff ("ns3::UdpSocketFactory", 
                      Address (InetSocketAddress (multicastGroup, multicastPort)));
-  onoff.SetAttribute ("OnTime", RandomVariableValue (ConstantVariable (1)));
-  onoff.SetAttribute ("OffTime", RandomVariableValue (ConstantVariable (0)));
+  onoff.SetAttribute ("OnTime", StringValue ("ns3::ConstantRandomVariable[Constant=1]"));
+  onoff.SetAttribute ("OffTime", StringValue ("ns3::ConstantRandomVariable[Constant=0]"));
   onoff.SetAttribute ("DataRate", DataRateValue (DataRate ("255b/s")));
   onoff.SetAttribute ("PacketSize", UintegerValue (128));