Hey JeffS
What is happening there is your script is being run twice. Once on the server, and once on the client. What you need to do is get the client to stop running it.
To do this, you'll want to do what Terox suggested. Add the line to your script (which I gather you've already done), and place a game logic unit.
To do this:
- Hit F1 and double click on the map... just like you were going to place any other unit
- In the Side dropbox (the one where you can select West/East/Resistance etc.) select "Game Logic"
- Now you'll have a game logic unit. Name it Server
It doesn't matter where you place this unit on the map. It is invisible, and the AI (or the players) won't even see it, let alone react to it. It's simply there to make sure the script can tell the server from the clients ;)
If you manage that, you should be getting only one unit created when you run the script.