Scout issue?
I have noticed that if you build a scout in a gravity well that already has scouts in it set to auto-attack (for mine clearing) the new scout will be produced with auto-attack on and you cannot turn it off. Usually happens late to mid game.
Another thing that has already been mentioned, I believe, is the AI's lack of capital ships. I will have 13 and the AI will have 2 or 3. This late game and the AI's are set to hard-aggressor. Thanks - J