I have been playing humans on a gigantic map in sandbox mode (normal rules, challenging difficulty) for quite some time now and am wondering whats up with the mega events. I read beta-AAR's where people were telling fascinating stories about events that had the potential to really topple the balance in a galaxy - so where are those pirate invasions, plagues and stuff - did I miss an option where to turn those mega events on and off or are they just happening very rarely?