My CanoScan 8800f has recently begun introducing vertical lines in all my scans. I believe this started occurring after I had removed the top cover multiple times to clean the dust from the underside of the glass (and then several more times to remove stubborn streaks). My guess was that some dust got stuck to the imaging components inside, so I took the cover off the actual scanning mechanism and hit the inside with a good blast compressed air. Even after all that, I still see these vertical lines along all my scans.
What could cause this and what can I do to resolve it (if anything at all)?