Problem with multiple actors of the same type overlapping another actor

Okay, so I am creating a game in which one of the functions of the game is that the user will drag and drop an actor into a box (which will be another actor), and when it enters the box, an attribute will be incremented. When it leaves the box, the attribute will be decremented. This works fine with one actor, but the game uses multiple actors of the same type. So say I have two identical actors that are meant to be dragged into the box. The goal would be for me to drag in one actor, and the attribute would increment to 1. Then I would drag in a second actor and the attribute would increment to two. However, it doesn't work that way. Instead, only the first actor increments it to 1, and the second actor does nothing. Sometimes, none of the actors can increment or decrement the attribute at all! What is my problem?
-update: Just checked, this same thing happens even with drag and drop actors of different types. Also, everything works like it should if I drag both actors in at the exact same time (basically, if I am dragging the identical actors one on top of the other).
-update: Just checked, this same thing happens even with drag and drop actors of different types. Also, everything works like it should if I drag both actors in at the exact same time (basically, if I am dragging the identical actors one on top of the other).
Comments
have you duplicate your main actor (alt+drag)?