After reading Timer.cs in the mono source, I'm not

convinced that timer.Enabled modification is thread safe.
I suspect the statsHeartBeat call to be one of our hot spots
because is tries to synchronize not with a lock, but by
disabling and enabling itself.  I've replaced that with a lock
in the hopes that this affects either the 100% bug, or the
invoke_void bugs.

OpenSim/Region/Environment/Scenes/SimStatsReporter.cs

@@ -138,8 +138,10 @@ namespace OpenSim.Region.Environment.Scenes
 
         private void statsHeartBeat(object sender, EventArgs e)
         {
-            m_report.Enabled = false;
-            
+            // Know what's not thread safe in Mono... modifying timers.
+            // System.Console.WriteLine("Firing Stats Heart Beat");
+            lock (m_report)
+            {
                 // Packet is already initialized and ready for data insert
                 
                 
@@ -256,7 +258,7 @@ namespace OpenSim.Region.Environment.Scenes
                     handlerSendStatResult(statpack);
                 }
                 resetvalues();
-            m_report.Enabled = true;
+            }
         }
         
         private void resetvalues()