Warlock-IMP

My warlock imp is not attacking unless i select his fireball on his menu. I will have him on defensive or aggressive stance and he will do no damage. will will get close to my target but do nothing. can anyone help with this issue? thank you in advance.

I'm sure you've found out by now, but I have to give the obvious answer... Have you right clicked the fireball spell? It will make him automatically use it by himself.