I am trying to print post card size on a PagePro 1350W printer. I set my page properties to width 5.5" and hight to 3.5" and do my work.
However when I try to print to default printer, I use a letter size as a "test" medium, it prints in the lower left hand corner not in the center top. So that means if I had fed card stock it would have missed the card completly.

What do I need to do?

tj

I believe the positioning should be up to your print driver, not Inkscape. Inkscape sends a 5.5 x 3.5 image and your print driver chooses where to put it on the page. When it comes to printing on a post card, so long as your printer knows the size of the post card it should not be a problem.