Well, I've tried 4 computers, one with a built-in RS232 port, one with PCI Card RS232 and two with multiple USB - RS232 powered and USB powered, all have the same result. Got a copy of the driver from Gary thinking it might be a different version with no change. I'm thinking I will probably have to send the whole 'shooting match' back and get SI to get it all working.
Thanks for all the help.
Charles