Creep Movement problem

[pyroclasm]

I'm making a game based on Enfo's Team Survival. I am spawning the creeps for Neutral Hostile so that I can use Warcraft's build-in Gold Bounty rather than having to make a trigger for giving players gold. However, when I order the units to move, they keep moving back and forth between the spawn and the waypoint, like this:

+------------------+
|    y  <----    x |       (x = spawn, y = wapoint)
|   ||             |
|   ||    +--------+
|   \/    |

If I order the creeps to move straight to the target (ignoring the waypoint), they run into the corner and then back. If I spawn units for Player 12 instead of Neutral Hostile, the creeps move properly. Why is this happening?

 

[Sargon]

Creeps have something called a "creep return time" or some such thing. Therefore, they eventually go back to their camp. You can change it in Advanced>Gameplay Constants.