diff -r 8e5aa0f947af src/wifi/model/sta-wifi-mac.cc
--- a/src/wifi/model/sta-wifi-mac.cc	Mon Mar 28 10:29:02 2011 +0100
+++ b/src/wifi/model/sta-wifi-mac.cc	Mon Mar 28 17:45:05 2011 +0200
@@ -145,7 +145,7 @@
   NS_LOG_FUNCTION (this << enable);
   if (enable)
     {
-      TryToEnsureAssociated ();
+      Simulator::ScheduleNow (&StaWifiMac::TryToEnsureAssociated, this);
     }
   else
     {