It's probably not a bug, but it should be one ha ha. I was in a war with the Krynn, and I basically had their last two planets surrounded, and was merely waiting for transports to arrive to take them out once and for all. One turn before they got there, the Krynn surrendered....not to me, but to the Korath, who had done nothing to them at all the whole game. Ticks me off. You shoudl only be able to surrendur to people you're in a war with.