I met a summoner on Tower:20 and its demons were doing nothing during the whole fight, they kept standing about 3 tiles away for about 10 turns. Only after summoner death they started attacking me. Maybe it has something to do with summoner being paralyzed often.
Huh. I haven't heard that one before.. I'll take a look though. Thank you. If it happens again, exit the game and zip up your Save directory for me, then PM me and we'll find a way for you to send it to me.