Index: trunk/Mars/mjobs/MJSimulation.cc
===================================================================
--- trunk/Mars/mjobs/MJSimulation.cc	(revision 19722)
+++ trunk/Mars/mjobs/MJSimulation.cc	(revision 19723)
@@ -237,10 +237,14 @@
     write.AddContainer("MCorsikaEvtHeader",   "Events", kFALSE);
     write.AddContainer("MRawEvtHeader",       "Events");
-    write.AddContainer("MMcEvt",              "Events", kFALSE);
-    write.AddContainer("MMcEvtBasic",         "Events", kFALSE);
     write.AddContainer("IncidentAngle",       "Events", kFALSE);
     write.AddContainer("MPointingPos",        "Events", kFALSE);
     write.AddContainer("MSimSourcePos",       "Events", kFALSE);
     write.AddContainer("MSrcPosCam",          "Events", kFALSE);
+
+    if (fOperationMode!=kModeData)
+        return;
+
+    write.AddContainer("MMcEvt",              "Events", kFALSE);
+    write.AddContainer("MMcEvtBasic",         "Events", kFALSE);
 }
 
@@ -909,5 +913,4 @@
     write3b.AddContainer("MMcEvtBasic", "OriginalMC");
     write4b.AddContainer("MMcEvtBasic", "OriginalMC");
-
 
     // --------------------------------------------------------------------------------