QTR-Quadtone RIP

Thanks for all the suggestions. Although it may be premature, I think I have resolved the issue. I have been using the front loader to avoid pizza wheels. I have used a piece of inkjet paper to facilitate getting the Pictorico into the printer, then removed it, and loaded the Pictorico by itself, and printed. This has worked fine for many months with no marks. The marks are a new issue. I have recently shifted to Cone inks and thought that might be the issue, but based on the advice that the front feeder was for thicker paper, I left the paper with the Pictorico and loaded them together and printed. The results are promising, but I will have to make more negatives to be sure. I appreciate everyone's help. I have no idea why this would all of a sudden become an issue when I have had success doing it the previous way.