--- a/src/devices/wifi/edca-txop-n.cc	Wed Oct 21 17:45:13 2009 -0700
+++ a/src/devices/wifi/edca-txop-n.cc	Thu Nov 12 05:05:44 2009 +0100
@@ -282,7 +282,7 @@ 
     }
   MacLowTransmissionParameters params;
   params.DisableOverrideDurationId ();
-  if (m_currentHdr.GetAddr1 ().IsBroadcast ()) 
+  if (m_currentHdr.GetAddr1 ().IsGroup ()) 
     {
       params.DisableRts ();
       params.DisableAck ();
--- a/src/devices/wifi/qsta-wifi-mac.cc	Wed Oct 21 17:45:13 2009 -0700
+++ a/src/devices/wifi/qsta-wifi-mac.cc	Thu Nov 12 05:05:44 2009 +0100
@@ -544,7 +544,7 @@ 
   NS_LOG_FUNCTION (this);
   NS_ASSERT (!hdr->IsCtl ());
   if (hdr->GetAddr1 () != GetAddress () &&
-      !hdr->GetAddr1 ().IsBroadcast ())
+      !hdr->GetAddr1 ().IsGroup ())
     {
       NS_LOG_LOGIC ("packet is not for us");
     }