Xsane Multipage HPJ4580

I’m trying to use Xsane multipage on a HPJ 4580. It pulls the pages through perfectly, creates the page images within Xsane multipage project window, but each image ends on 791 pixels wide and 8 pixels high. Every page is the same. Has anyone encountered something like this before?

I usining 12.3 and the HP appears all set up and Xsane too. It works fine otherwise.