Lag Compensation
Lag compensation for fired bullets is enabled by default on SA-MP servers since 0.3z. It can be toggled using the 'lagcompmode' server variable (in server.cfg). Setting it to 0 will disable lag compensation completely and players will have to lead their shots (fired ahead of targets).
Disabling Lag Compensation will make OnPlayerWeaponShot to don't be called.
This variable can only be set in server.cfg.