When printing 13X19 from InDesign CS5.5 on OS X Lion to R1800 with Gutenprint 5.2.3 driver and Printer Settings set to Photo Glossy paper, Super Photo, the output is shrunk to a fraction of that size. To rememdy, checked for driver update, restarted hardware, checked settings, i.e. deselected scale to page. A test page at default setting of 13x19 plain paper does not produce the same unwanted shrinking effect. Suggestions?
Export a PDF and print that.
Tried. It failed.
Did you set up a custom size, or are you using a preset? Whichever, try the opposite.