Always wait until you see the message “Node manager terminating” before you restart Blueworx Voice Response. Otherwise, all the processes may not have had a chance to complete their cleanup activities. How you restart the software depends on whether you are still logged on to AIX.
There's more information about starting the system and about dtuser in the Installation information.
If you need to shut Blueworx Voice Response down immediately after you have restarted it, use the DT_shutdown command, which ensures that all the processes are shut down cleanly.