I think feelotraveller was right on d), i think the base was damaged and not having enough material to complete construction and repair the damage they went back to get more materials.

<t> In an effort to deter pirate attack, like most I imagine, I arm my construction ships. I do notice though after interrupting construction on a base to fight off an aggressor and asking con ships to repair/continue building the base, they feel the need to run home first. Are they in need of more ...

<r> Trying to shift the border was an idea. It was an odd situation because the system in question was within the sphere of both of our planets capitals. We started awfully close together. I imagine war would have been the likely outcome before any border shifting though. I moved onto another game ...

Thanks! I figured it was just a patch change somewhere along the way. Shame though, I liked the idea of balancing diplomacy/discretion/material needs...and I needed me some Silicon at that point in the game. >=)

<t> Relative noob here. From some of the insinuations I've read/seen ingame. We should be able to build bases and even found colonies in foreign territory (without permission/treaty) if desired (with a diplomatic penalty of course). The one time I tried this I couldn't seem to do it. Buttons for ...