diff -u -r1.13 -r1.14
--- SeedTracker.java	20 Jul 2010 17:51:36 -0000	1.13
+++ SeedTracker.java	13 Nov 2010 02:15:17 -0000	1.14
@@ -125,15 +125,15 @@

         //  Make tracks from the final list of track seeds
         _maketracks.Process(event, trackseeds, _bfield);
 

-        //  Save the MC Particles that have been seeded
-        Set<MCParticle> seededmcpset = _finder.getSeededMCParticles();
-        List<MCParticle> seededmcp = new ArrayList<MCParticle>(seededmcpset);
-        event.put("SeededMCParticles", seededmcp, MCParticle.class, 0);
-
-        //  Save the MC Particles that have been confirmed
-        Set<MCParticle> confirmedmcpset = _finder.getConfirmedMCParticles();
-        List<MCParticle> confirmedmcp = new ArrayList<MCParticle>(confirmedmcpset);
-        event.put("ConfirmedMCParticles", confirmedmcp, MCParticle.class, 0);

+        //  Save the MC Particles that have been seeded / confirmed if diagnostics are enabled
+        if (_diag != null) {
+            Set<MCParticle> seededmcpset = _finder.getSeededMCParticles();
+            List<MCParticle> seededmcp = new ArrayList<MCParticle>(seededmcpset);
+            event.put("SeededMCParticles", seededmcp, MCParticle.class, 0);
+            Set<MCParticle> confirmedmcpset = _finder.getConfirmedMCParticles();
+            List<MCParticle> confirmedmcp = new ArrayList<MCParticle>(confirmedmcpset);
+            event.put("ConfirmedMCParticles", confirmedmcp, MCParticle.class, 0);
+        }

 
         //  Clear the list of track seeds accumulated in the track finder
         _finder.clearTrackSeedList();