I just had this happen on Friday and of course it wasn't on 10 or 20 decals but 1000 small credit card size. I had 5 sheets of 250. Once I noticed the double cut I let the sheet run to the end and then went back into flexi and deleted the addtional cut and then I recreate the sent file and send it out for print, but I dont print and then use that file for cutting. Worked like a charm. As to how the double cut line got there, I have absolutley no clue. I set up in Signlab and then import eps files to Flexi.