One part of the "AI" isn't really AI. A lot of people think of the trade screen in the game as being "AI". But it's not. It's basically just a dialog full of weighted values.
The real AI may, for instance, call up the trade screen. But the actual valuing of items in the trade screen (money, techs, ships, planets, etc.) isn't in my area (the AI) but is instead just a table of values to weight everything.
Which means, of course, that it's exploitable.
Creating a negotiation screen like this is non-trivial.
For instance, in GalCiv, you can research diplomacy techs and get the super ability Diplomacy which gives you a huge advantage in negotiations. But at the same time, we can't let people trade say 100BC for 101BC or else they can really exploit the game. And that's the kind of thing that is more difficult to keep from happening than one might think.
In Civilization 4, the solution was to pretty much make it so that you could only trade apples for apples (techs for techs for instance). That way, players couldn't easily exploit the AI.
In GalCiv, we slog through with trying to let people trade ships, techs, money, treaties, war proposals, etc. for any combination of those things.
But the downside is that some people will find exploits. There is no practical solution other than to remind people that it is a single player game and if they want to cheese the computer opponents, that's really their busines.
We also try to do updates to the trade screen "AI" so that it is better in negotiating. But there are just so many variables to take into account.
If you have a particular "stupid" trade screen behavior, post below and I'll take a look at it. 