I remember seeing this awhile ago, but I can't find the thread thanks to the search function only searching titles.

Anyway, when you have transports (or sometimes just one) flying around an AI starbase, it meets the conditions of an invasion buildup and makes the AI likely to declare war.

I post this as a bug, because the text in the war declaration message suggest that Stardock meant for the transport buildup event only to trigger when near planets, not starbases in another race's terriory half the map away from a habitable planet.

Not a gamebreaker, but it's disconcerting to have half the galaxy declare war on you because they had mining starbases in the same sector as an unrelated planet you're in the middle of invading.