Hi,
One thing that you may want to check is the dialing prefix and other settings in the Serial Port Options under Options»Serial Ports. These settings are not distributed by your process file.
If those options are the same on both machines, then you may want to try
Logging the communications on that COM port to a file. This will show you what Lookout sent and received on both computers and may show what is different, if any.
Hope this helps,
Mike