Some time ago I experienced a strange interaction which I was not aware of. My character was perma-invisible from a pool and created a familiar. [Side note: as it turned out, perma-invis. is a quite nasty thing in the early game, you cannot enter to Arena for example.]

After some time, the familiar stopped being such! His status became "does not care about you" (i.e., non-aggravated and not friendly). I am sure that did not shoot him, not triggered traps etc.

WTF?!!! I mean, it is probably because of invisibility but why? I wanted my precious companion to clear Darkforge and maybe ToEF