QuadtoneRIP prints image at half size

Hi All,
Still getting my feet wet with QuadtoneRIP. So far I’ve discovered several novel ways to turn printing paper into recycle stock. But I could always figure out what I did wrong. Not this time. I’m trying to print a 15 x32 on my 3880 using a 17 x 36 as a custom paper size. It prints the complete image but only at about half the size. This only happens with the custom size. I’m using version 2.7.0. Thanks for any ideas.