Ordering Neutral Units to 'Move To'.

I got a problem. I'm creating two neutral hostile units very far apart, with a rect right in between them. After they are created, I set a variable to each, one to Lower and One to Upper, then I name the rect 'Spawn' and use these actions:

Unit - Order Lower to Move To (Center of Spawn <gen>)
Unit - Order Upper to Move To (Center of Spawn <gen>)

Now the problem is.. they will run about half-way to the rect, turn around, and go right back to where they came from.

Whats the deal? And how do I fix it?

The Neutral AI can cause neutral units to return to their original position in two situations.

1: They have exceeded their "chase time". This can be modified in the gameplay constants "Creep return time"

2: They have exceeded their "chase distance", as above, modified by tweaking "Creep return distance".

In a nutshell, set both those fields to 99999.

Alright I made the two units owned by Player 7 (Green), but they still return to their original positions. I don't want to modify the two values in the gameplay constants because it would make all of my creeps follow you forever, and thats not something I want.

I set its acquisition range to 99999 and its sight in day/night to 99999, and they still don't seem to have any effect on how long they willl run.

The main reason I'm doing this is because I want the unit to be able to chase you all around the map, for unlimited time or distance, without modifying gameplay constants.

Make them player controlled then :I

... but I want them to be computer controlled.. because I'm doing this for the final boss, and I don't think it would be fair if he was player controlled.