A "Transport" is a COMM port. By design, an RS232 communications (comm) port can only serve a single application at any given time. Devices such as Palm Pilots install drivers that will take command of communications ports even if the unit is not attached to the computer. Modems too assume complete command of ports.
Close all other applications.
Assure that the instrument is physically attatched to the selected port.
Experiment by changing ports in the SW; try com1 then com2, etc.
If there are other RS232 devices disable them and close their drivers.
If the customer continues to have communications issues, "Transport" issues, there is a chance that the computer's RS232 port is defective. If possible use HyperTerminal on a different PC to assure that the handheld is communicating as designed. If this can be proven then the PC will need to be repaired.
If this does not resolve your issue please click here to go to "My X-Rite" where you can create a new support case. One of our Technical Support Reps will then contact you for further assistance.