JVC digital camcorder model GZ MG330AU

Our JVC digital camcorder using Enviro software will transmit to the PC but when a burn disk command is given, we get the message "Please insert disk" when there is a disk in the HP DVD external burner (we got a similiar message from a LG burner which indicated that the hardware could not be found although it was recognized by the PC when installed). Nothing happens. The camcorder says it is compatible with DVD-R. We have tried using different PC's and get the same message anyway. None of our computer saavy friends can figure it out. Can you help? Please advise. Thanks.