Whilst working on a project that aims to test agent models, I've encountered somewhat of a problem. When running the example "Flockers" program without a GUI, the results compared to a non-GUI version with the same seed seem to differ significantly. More specifically, the positioning of the "dead" flockers appears to be the same but those of the live flockers are vastly different at the same number of iterations. Both give consistent, but different, results each run. I have been running them as follows: Non-gui- using ARGS input of "-seed 1 -docheckpoint 1500 -until 1500" Gui- Setting seed to 1, set to stop at 1500, start new simulation I have then been loading the checkpoint to compare them visually via the GUI. Is there something important that I am missing that is causing the GUI and non-GUI versions to give different results? I haven't been using MASON long so may simply be making a mistake or bad assumption. Many thanks, Chris