QTR-Quadtone RIP

I just received my 3mk inks from mis ink supply, for my epson 1800.
With the quadtone software:

I seem to having trouble getting my image center on the paper{8x10}
I have the scale to fit and centered checked,but the page comes out
uneven.
Also,I know I need to use Matte paper,but I put in a luster paper in
error and the image came out perfect,looks exactly like the matte paper

Any help/ advise would be greatly appreciated on anything related to
using quadtone properly.
I've read and re-read most of the help topics/instructions from Paul
Roark.
What am I missing?

Mike