Sorry beckie!
There is a good tutorial in the 'Cherrypicker's Guide' that you can find down at your local bookstore. Wouldn't hurt to grab a coffee, sit down and read the capture before putting it back on the shelf.
The key is that the 'doubled' area needs some characteristics of it's own. Look for an actual 'ridge' in the numbers where the doubling occurs. Yours is flat and shelflike.
What finally clued me in was to see a real one and how it looks under the magnifying glass.