I have been having lots of problems printing my 3x4 cards with my Cannon Selphy- but came across a workaround I'm sahring on the ForeverJoy blog today! - http://goo.gl/AyOd9B
Great tips! I had a really old Selphy and it wasn't working with my laptop anymore so I got rid of it, but this is great to know if I get one again. It was handy to have sometimes!