Mine are marked too, but since I didn't want to take a chance, I verified with a magnifier. Now that I'm sure the marks indicate "down", I'll just refer to the marks in the future. Thanks for mentioning it.
One thing I can't get it to do is toe nail without the pins making a U-turn. :) I tried ply/ply and oak/oak. More than 1/2 the pins did a u-ey.
Dave