Why does my cutter always do stuff like this on larger scale cuts (see attached jpg). I have a MH871-MK2, I use SignCut Pro on a Mac, and I hook it up with a serial keyspan adapter. It cuts diagonal lines though parts and then continues on as if it was done cutting that area. It does pretty much the same thing regardless of if I use the pen on paper or the blade on vinyl. Also attached is a pdf is what the design is supposed to look like. I'm trying to cut it 22"x22". PLEASE HELP ME!