Just noticed a bug - when you offer a mission to an ai and press submit the resources you're offering are deducted from your pool. If they then reject it you don't get those resources back. I haven't noticed this happening all the time, though it might have been and I just didn't realise.

Plus, the ai seems to be signing cease fires with one another despite having 0% relations, whilst they won't even sign a trade agreement with me ever (though maybe this is because they haven't researched the tech - this behavious may not have been implemented yet).