This happens to me sometimes when playing. Sometimes my hireling will get stuck somewhere, not automatically reappearing close by if we're separated. I can get them back by going back to town via town portal, exiting the area, or casting teleport. But then when I do, something has changed. The monsters completely ignore my merc and focus entirely on me. This can be very dangerous if playing as a caster because then I'll have lost my meat shield. Strangely though, monsters who attack from range such as archers, casters, or those who attack primarily from range will still attack him or her. Has anybody ever had this happen to them? What do you think is causing it? How can it be prevented?