Pop-up from Office Communicator

We are testing office Communicator 2007 and have run across a small annoying issue.

A new Dell E5400 was recently deployed and any time the user logs onto the laptop connected to a network outside our domain, he gets a window right after Communicator loads stating the exchange server can not be contacted.  Selecting cancel on the window closes it and the little yellow triangle with exclamation point shows on the Communicator icon in the system tray.

This is expected behavior (not able to connect to exchange off domain) but we have this client loaded on other laptops and no one else gets the pop-up window concerning exchange.  Once loaded the yellow triangle just appears on the Communicator icon as it should.

Is there a setting or way to prevent the pop-up window from coming up when a user logs on off the domain?  and why does it only happen on this one laptop and not the others?

We don't to start getting a phone call from every user that gets this pop-up thinking it is an error.