A couple months ago I purchased a new color scanner (thanks, Vista) – a Canon LiDE70.  I noticed a few weeks ago that I was having problems scanning color images, and it popped up again this weekend.  I would get these very odd colored, horizontal lines through the image, most visible on black and dark colors.

Since I actually needed color this time, I had to figure out what was going wrong.  I did a half dozen scans, each time playing with a few settings to see if it would resolve itself.  I looked for new drivers – none.  As a last ditch effort, I changed which USB hub it was plugged into and it worked!

Never would have guessed that would have been a problem.  I hate USB hubs.