Help getting Canon LiDE 30 USB scanner to work

[walt]

Vincent Stemen wrote:
We had this scanner working once before with an earlier version of
Dragonfly but do not seem to be having any luck now.
sane-find-scanner  says it found the scanner
     found USB scanner (vendor=0x04a9 [Canon], product=0x220e [CanoScan],
     chip=LM9832/3) at libusb:/dev/usb1:/dev/ugen0
but

scanimage -L  says
     No scanners were identified...
My symptoms were not quite the same as yours, but I had success when
I unplugged my scanner before boot and then plugged it back in after
the system was up.