Was playing tonight, found a bug (dunno if it has already been reported)
I had a planet with about 2.6 billion folks. On this planet, I built a transport with 3 adv modules. Did a right-cluck to launch the transport with a full complement of troops:
Ship was launched with 2.6 billion. 2.6 billion folks were still on the planet. Docking the ship there again caused the population to go to 5.2 billion
Malkleth