Hi, You are wright, the problem was already mentioned and is caused by the new random engine. In fact this new engine takes different seeds than the last one but the gjs program was not updated to produce these new seeds ... To fix this out you have to change the definition of the random engine at the beginning of the main program to set the old one instead of the new one. I send you with this mail the file Gate.cc where I did the modification. Just replace the original Gate.cc file by this one and recompile, then it will use the old random engine with the old seed files generated by the gjs program and it will work fine. A new patch is coming soon with which you can manage all the random engines and seeds aspects with macro commands. Sorry for your CPU time lost ! Cheers, Simon <div class="gmail_quote">On Wed, Dec 10, 2008 at 4:01 PM, KB <<a href="mailto:kd8had@gmail.com">kd8had@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hello All, GATE version name: gate_v4.0.0  (20-August-2008). I am running SGE. Using gjs, I split the main macro into 25 parts and submit them as a array job using qsub: "qsub -t 1-25 -V /home/data/.Gate/Hits/Hits.sh" This produced 25 root files which I am supposed to merge with gjm. I did so and noticed that the resultant root file has some strange behavior when some parameters were histogrammed. There was a periodicity of 25. So I randomly picked 2 of the 25 root files  and using root printed out the events. They are unfortunately identical. This makes the culster version of GATE almost useless (at least for me). Does anyone else notice the same thing? Here is some output from running root: I open the first file: root [0] TFile f2("CylinderHitsSingleGamma3.root") root [1] Hits->Show(1) ======> EVENT:1  PDGEncoding     = 22  trackID         = 4  parentID        = 1  time            = 0.400002  edep            = 0.0018285  stepLength      = 0.00627867  posX            = 455.453  posY            = 75.4412  posZ            = -30.2955  localPosX       = -1.67338  localPosY       = -0.606797  localPosZ       = 0.267013  gantryID        = 0  blockID         = 0  crystalID       = 339  unused3ID       = -1  unused4ID       = -1  unused5ID       = -1  photonID        = 1  nPhantomCompton = 6  nCrystalCompton = 0  nPhantomRayleigh = 0  nCrystalRayleigh = 0  primaryID       = 1  sourcePosX      = 17.0792  sourcePosY      = -100.416  sourcePosZ      = -49.8924  sourceID        = 0  eventID         = 3  runID           = 0  axialPos        = 0  rotationAngle   = 0  volumeID        = 0,                   0, 0, 339, -1, -1, -1, -1, -1, -1  processName     = LowEnPhotoElec  comptVolName    = wholecylinder_P  RayleighVolName = NULL Here is the 1st event  from another root file: root [0] TFile f1("CylinderHitsSingleGamma10.root") root [1] Hits->Show(1) ======> EVENT:1  PDGEncoding     = 22  trackID         = 4  parentID        = 1  time            = 1.8  edep            = 0.0018285  stepLength      = 0.00627867  posX            = 455.453  posY            = 75.4412  posZ            = -30.2955  localPosX       = -1.67338  localPosY       = -0.606797  localPosZ       = 0.267013  gantryID        = 0  blockID         = 0  crystalID       = 339  unused3ID       = -1  unused4ID       = -1  unused5ID       = -1  photonID        = 1  nPhantomCompton = 6  nCrystalCompton = 0  nPhantomRayleigh = 0  nCrystalRayleigh = 0  primaryID       = 1  sourcePosX      = 17.0792  sourcePosY      = -100.416  sourcePosZ      = -49.8924  sourceID        = 0  eventID         = 3  runID           = 1  axialPos        = 0  rotationAngle   = 0  volumeID        = 0,                   0, 0, 339, -1, -1, -1, -1, -1, -1  processName     = LowEnPhotoElec  comptVolName    = wholecylinder_P  RayleighVolName = NULL The only thing that changes is the time. Everything else is identical. Printint out the other events shows the same similarities. Karthik. _______________________________________________ Gate-users mailing list <a href="mailto:Gate-users@lists.healthgrid.org">Gate-users@lists.healthgrid.org</a> <a href="http://lists.healthgrid.org/mailman/listinfo/gate-users" target="_blank">http://lists.healthgrid.org/mailman/listinfo/gate-users</a> </blockquote></div>