The rolling is prediction of next crop mark alignment due to loading the material at the wrong angle as crny1 has said. The only other time we have seen this is in a copy and paste situation where the cut file being used is not the correct cut file (but extremely close).....usually in a duplicate print and cut job where operator tries to cut all print jobs from one cut file but something was slightly off in the dimension of the print job.
However it's probably not the case in your situation if your results are the same on 2 Roland machines. It maybe best to try and figure out some point of reference on that second crop mark visually. Usually where people go wrong is they stand right there at the first crop mark and get it lined up, they look to the left crop mark....it also from that angle looks correctly lined up but it's actually too far back....drop the lever, hit setup and send and then you rolling problem occurs.
If you can't figure out a good visual reference on the print....try getting a guillotine or some
paper trimmer that will allow you to trim the front edge of the substrate that can correlate with something on the printer to line up.