I'm playing that campaign mission where you have to capture the planet Charon. It's currently held by the Dread Lords, and for some reason that completely baffles me I can't attack it. I have a fleet sitting there ready to take out the ships in orbit, but trying to attack the planet does nothing, just like if there were no ships in orbit. But there are ships in orbit, so I can't move a transport in either. I'm assuming this is a bug, though I guess it could have something to do with the "Salvation Device" I'm supposed to be retrieving from the planet. I don't think I can complete the mission if I don't find a way around this. Is it even possible to culture-flip the Dread Lords?