Creep Respawn Trigger

I'm trying to make a trigger that will respawn all the Neutral Hostile units 30 seconds after they die with just 1 trigger.

Event
Unit - A unit owned by Neutral Hostile Dies

Conditions
-None-

Actions
Wait 30.00 seconds
Unit - Create 1 (Unit-type of (Triggering unit)) for Neutral Hostile at (Position of (Dying unit)) facing Default building facing degrees

But the creeps don't respawn. Its on and everything. What am I doing wrong?

Edit: I am testing the trigger on units that are spawned by a trigger, not there initially, could that be screwing it up?

Change Triggering Unit in Unit-type of (Triggering unit) to Dying unit

Unit - Create 1 (Unit-type of (Triggering unit)) for Neutral Hostile at (Position of (Dying unit)) facing Default building facing degrees


y are u using triggering and not dying? just wondering

Because imma n00b.

Is a method like this usable for a map full of npc creeps?
Will there be performance hits for lots of waits?