Hi, I used GP by ECJ to do experiments and had two findings below. Hope you can help to explain. 1. Same PC, same ECJ parameter setting, same seed number, experiments were run at different time. One was run at end of 2009; the other was run yesterday. The results were different. 2. Different PC, same ECJ parameter setting, same seed number, experiments were run at different time(around 2 months time). The results from 2 pcs were same. Many Thanks