I had the same problem. I posted the question on the m.com forum and Cerberus gave me this answer:

"It took me MONTHS to fine tune my scanner settings to get what I wanted.

The scanner-producing companies clearly believe people will only ever need to scan either a text document or a photo and therefore make no effort to meet the needs of anyone else.

I tend to find that you need to lower the contrast for the scanner to pick up the details, and then use Photoshop to bring it back up again afterwards."

It worked for me, it can work for you. And that goes for most pics.

I wish I had a working scanner of my own so I could do that, but thanks for that the advice

... by the way, nice drawing