You may be on the right track -- maybe there is a problem with the cable or with the scanner itself.

I unplugged and unattached the scanner prior to boot. Then, after starting Knoppix I plugged the scanner in -- there was no resulting beep or noise of any kind. Then I ran insmod, but still received the same responses from usbview, scanadf, and even with lsusb.

I'm running Knoppix 3.4, which as far as I know is the latest version.

I'm starting to suspect that you may be right about it being a hardware problem, rather than a Knoppix problem....