Hi, james

I don't have the portrait, but i have a cameo one. What kind of difficulty in it?

The machine was incorrectly reading the registration marks, and cutting the paper incorrectly;  the cuts didn't line up with the printed design.  It was strange because the cut pattern was skewed, the first few inches of the page matched, but further down it got more and more offset.

I think i fixed it out by using lighter colored paper (though I wish I didn't have to) and by making sure the machine was set on a table where the plastic mat didn't bump into anything as the machine moves it around.  I think it was gently bumping something and slightly lifting it as it detected the marks.  Maybe?

Seems to be better now.  thanks for asking!
Do you have any other advice?

Ah, I also experienced this one, I made hundreds pages (maybe) to get - finally the correct one, I found this failures in a forum and its cause is when the censor error in reading the registration mark

Maybe these answers could help u:

1. u should calibrate it (calibration), if okay then no problem with it

2. u should make sure that printed paper stick on the cutting mat, cause it might slightly move if don't stick enough. u can use the spray adhesive to increase the stickiness.

3. make sure that your lighting is bright enough especially in censor area and the printed page, 

There's many things could distract the sensitive censor, make sure there's no other similar or black area in registration mark corner, the lighter colored paper is better than darker one

and yes, if it bump into something, this could happen too.

Hopefully this can help u :)