Game 1:
I have alliances with 3 of the 5 remaining AI -- Torians who I am close with and Drengin who hate me. The Drengin only have a couple planets left and are so close to my planets that they're almost defecting while the Torians are on the other side of the map pretty much all alone.
Suddenly the Drengin declare war on me. I get messages from all three of my allies saying "We're honoring our alliance and declaring war on the Torians." The Torians are still at peace with (and trading with) me, my alliances are still active, and none of my allies are at war with the Drengin. What gives?
Game 2:
The Drath declared war on me and I kicked their butts, snagging a few planets and then charging them an arm and a leg for peace. After a few more turns of peace with the Drath I declare war on the Yor. The Drath then immediately say "you may have beaten us, but we'll always hate you" and surrender to me, despite the fact that nobody declared war on the Drath and they're at peace with everybody.
Is it getting confused about which race is in which player slot or something? In both cases I already had the game in the bag by the time it messed up, but it still confused me.