For anyone else who is thinking of doing this project, here is an import bug report. This has been mentioned in relation to a particular model of Logitech mice, but appears is caused by any kind of USB device.
The softrock bios does not like to have ANY id but #1!
Symptom: You plug in your USB device after step 3 in the instructions, but get the message from windows “Unknown Device”, despite having good drivers installed.
Cause: Another device already has id 1, and the system is offering another to the softrock. The softrock will ignore the hand shake, and windows will report the error.
Temporary workaround: Unplug every USB device on your computer, including any mice and keyboards. Wait a moment so that Windows detects all of them are gone. Plug in your softrock. It should be detected. You can now plug back in everything else.
It sucks, but it’s a necessary thing at this point.