aperture 3x3 image on 4x6 paper

I'm pretty good at using Aperture, but I'm having problems with this one type of print.

I want a 3x3 image printed on a 4x6 photo paper. I want the edge to bleed on the top and on the left.

Here are my settings:

- paper 4x6 borderless

- image size 3x3

- landscape

- row = 1

- column = 1

- image per page = 1

But the margins won't zero out. Every time I change the left margin to 0 the right margin jumps to 2.75 and can't be changed. If I can change the righ tmargin, then the image size changes to 3 x 2.75. I was able to setup a 4x4 print with top = 0 and left = 0 and it printed great. Why is 3x3 giving me trouble?

I print custom size prints all the time, but I'm totally stumped on this one. Any suggestions on what's going on? TIA!