One problem I've been noticing when editing is that my printer / scanner seems to have a tendency to do one of two things:
1.) If the card isnt 100% pressed into the glass, it leaves a rainbow tint to certain colors and parts of the card (I assume, it may just hate certain shades of Gray / Black).
2.) Upon closing the lid, sometimes (more then I'd like) it shifts the cards around and makes them crooked. Now, this would not be a problem if they were in the middle of the scanning glass and I use a program to straighten them (if I could), but due to the way I scan them, this problem ends up cutting off small parts and corners of the cards.

So, please forgive any minor mistakes to it, though you'd have to look REAL hard to see some of the issues caused by #2.