--- a/src/wifi/model/mac-low.cc	Tue Oct 08 11:30:26 2013 -0400
+++ a/src/wifi/model/mac-low.cc	Tue Oct 08 11:47:07 2013 -0400
@@ -1159,7 +1159,7 @@ 
 void
 MacLow::NavCounterResetCtsMissed (Time rtsEndRxTime)
 {
-  if (m_phy->GetLastRxStartTime () > rtsEndRxTime)
+  if (m_phy->GetLastRxStartTime () < rtsEndRxTime)
     {
       DoNavResetNow (Seconds (0.0));
     }
@@ -1173,7 +1173,7 @@ 
       (*i)->NavReset (duration);
     }
   m_lastNavStart = Simulator::Now ();
-  m_lastNavStart = duration;
+  m_lastNavDuration = duration;
 }
 bool
 MacLow::DoNavStartNow (Time duration)