When I stack raw files, the right hand side of the final stack is stretched and distorted. The left hand side and central area is ok. This has happened with every stacked raw file, but doesnt happen with jpegs. I have tried stacking the same images in two other packages with no problems. When I save the image and then re-open it there is no problem. I had rejected several perfectly good images before realising it. This is an intermittent fault.