No luck so far...
Well, I picked up a copy of Virtual PC 7 with XP Pro, and a Keyspan high-speed USB to serial adapter. I've tried every configuration I can think of (both ways of emulating the COM port, and all available baud rates), and I can't get the computer to connect to the scanner using either the scanner control software or the firmware updater. Any suggestions would be appreciated--between Microsoft, Keyspan, and Uniden I don't know who to turn to for tech support...