I may have to retrack my previous statement. Now that I have my PCR-1500, it appears the USB port on the radio may in fact be an internal USB-to-Serial adapter! The software USB port setup is interpreting it as COM-4 (which is a serial port). So the new software may work with the PCR-1000.
It should be noted however that the sound recording abilities of the new software, acquire the audio though the USB cable, so it's pretty safe to assume that feature in the new software would not work, if the radio was connected to a serial port. Of course there are workarounds for that.