FWIW, I think Canon has gone downhill in QA recently. I have their 8800F scanner and it puts odd, random streaks on film scans -UNLESS I prop the lid up about 1/2 inch. Odd, but it works. I recently bought a Canon SX200 digicam and less than a month later it was off to Canon for repair.
On the other hand, my multiple Canon FD, EOS, and DSLR bodies all work just fine. Maybe their newer stuff is slipping thru the QA cracks.