LG VX-8100

i just bought a verizon 6100 cable for my 8100 phone. installed the drivers(lgusbmodemdriver4.5), plugged in the phone - it registered fine - it communicates fine in the device manager (winxp) - com3. installed qpst - it doesn't let me add any new ports(error reading them), whether they are in use or not. so i changed the port# that is assigned to the phone to com2 (com1 and com2 are showing in the qpst configuration by default for me). now it reads com2 as usb but says "no phone"(phone is dun enabled for cable and pc connection is set to usb). any help is greatly appreciated.