Am 18.06.2011 um 14:07 schrieb Mathieu Dupont:

However, I get 3 dashes in the left margin, one about half-way the paper height, one about 2 inches above it and one about 3 inches below it.

No matter what I put in the letter, their positions don't change, and they appear on every pages.

The three lines are for punching and folding the letter, you can hide them with

\setupletterstyle[marking=no]

Wolfgang