Hrm... curious. It did have a weird attack pattern, run up and shoot command center, fly away (cue cloak), then repeat. Maybe the AI is learning too much? Or maybe that can't-decide-whether-to-hit-something-important-or-a-harvester bug is back again.
That part sounds like it could be a bug, but I haven't really duplicated it in recent releases (since the other fix). I'll keep my eyes out for it, though.
If I can get a decent save game where it's ping-ponging again I'll upload it. Unfortunately I only just fixed the hole in my defenses that was causing this half an hour ago.
And on an unrelated note; I just wandered into a nicely defended base of a mix of teleport turtle and entrenched homeworlder with a large chunk of ships. Upon stabilising myself and regrouping from ye-olde-mass-fireworks entrance, I noticed that I had an almost identically sized large chunk of ships, and 70 Engineer Drone Tech III's (yay for parasites!). Given that I can only barely get 11, I think this AI cheats.
I'm still being taken down one at a time by an annoying ion cannon, but my force suddenly becomes a lot healthier a lot quicker now.