Hi all, Just to say that I "succeeded" to reproduce the problem mentionned by Irene and Jasmine with the Gate own coincidence sorter. So it demonstrates that the problem does not come from the Irene and Jasmine's own coincidence sorter. Results are as follow : --> From Gate_3.0.0 : (results are correct)  *  Acquisition start time = 0 [s]  *  Acquisition stop time  = 1 [s]  *  *  Total number of Singles : 864134  *  *  Total number of true    : 864024  *    --> percentage : 99.9873  *  Total number of scatter : 110  *    --> percentage : 0.0127295  *  *  Total number of coincidences : 62100  *  Number of true inter coincidences   : 0  *  Number of random inter coincidences : 684 --> From Gate_3.1.2 : (results are not correct)  *  Acquisition start time = 0 [s]  *  Acquisition stop time  = 1 [s]  *  *  Total number of Singles : 864633  *  *  Total number of true    : 864514  *    --> percentage : 99.9862  *  Total number of scatter : 119  *    --> percentage : 0.0137631  *  *  Total number of coincidences : 56394  *  Number of true inter coincidences   : 3266  *  Number of random inter coincidences : 726 So now the problem is obvious, and we will track it and hope to fix it as soon as possible. Thanks again to report these bugs. Have nice holidays, Cheers, Simon