Change Software Update Server location

I don't want all the Apple software updates stored on the startup disk, especially when I a have 1 TB drive in the slot next to it. I've tried changing the location in Server Admin / Software Updates to a different location, but now I'm getting the following error when trying to check updates on a client: "The Software Update Server (servername) is not responding". What else needs to be changed? BTW, this is Snow Leopard Server.

Thanks,
Kelly