If you have been using a USB scanner and upgrade from Edgy to Feisty, you may find that your scanner no longer works.
Read it here
These notes may help. There is a long thread about this check here . The problem seems to lie in the usb suspend functions built into Feistys new kernel in order to keep laptop users happy.Here are a few tricks taken from the above thread that might get your scanner going again. They did for me.