Found this while I was pulling my hair out. I finally got my darn unit to sync via serial. Even with a usb to serial converter connected to the cable made below in the link. The link below shows how to make the proper cable. Apparently there are 3 different types of null modem cables. WOW!
Here:
http://www.smacs.f2s.com/Hardware/PenCentra/pencentra.html
Ardvaark
Oh! Joy!!