E525w not picking paper (cards)

Hi all.

I would like to print on postcard size paper, 5.5" by 3.5". These are professionally printed greeting cards, with a glossy side.

I was able to define that custom size and select it from the printer properties dialog.

But the paper never gets picked up properly. Soon after the printer starts  up and wants to feed the paper (cards) I get a "paper jam" error. There never is a real jam; the paper just doesn't get fed far enough to jam.

Ironically, when I put the cards upside down they get picked and printed just fine. But that is not good; because then the address ends up on the glossy side.

I have no problems with regular paper, envelopes, and card stock.

Does anyone have any suggestions?

Thank you.