For what its worth, usb-2 is supposed to be backwards compatable to usb-1.1. I have heard of cases where devives that are made to be usb-1.1 not working if a usb 2.0 cable is used.
So step 1, I would locate a cable that is usb 1.1 as opposed to a usb 2.0 cable and see if it makes a difference. That also might show if you have a defective usb cable.
Step 2 would be to go to the scanner makers web site and see if they have anything on that problem.----also find out of the scanner is supposed to be usb 1.1 or usb 2.0----if its supposed to be usb 2.0 and you are using a usb 1.1 cable, wierd things could also happen.
Just my take on the matter-----others may have other inputs.
But always remember step 3-------beat your head against a wall repeatedly and hard----you will feel so much better when you stop.