hi Beth:
I just passed your e-mail to our engineering team. we appreciate the opportunity to investigate your very strange problem. we can't foresee all of the combinations of commands that may be sent to the serial port. you may be sending a valid stream of data that causes the dectalk usb to go in boot strap mode. we will do our best to come up with the problem and find a fix for it. take care and thanks again c u mike