By the way, I have now returned two of these. The first one for light vertical streaks that showed up in skies and the replacement in addition had a huge yellow streak on the left side of all scans. The replacement was even worse than the original!!
These scanners have huge maufacturing problems. They were rushed to market probably to compete with the Epson 4870.
I have my doubts as to whether Canon does any quality control on these at all. Don't waste your money on one. I am back to my 4870 full time.