Hello;
I have a 1000s and shoot b & w thru it. I have never had a roll run tight thru it and if I did, the dark bag would come out and unload the camera. Just taking a guess here but thinking the backing paper was wedged or torn causing the film to ride up against the focal plane shutter causing scratches and slowing the curtain explaining uneven exposure. Next time unload the camera and investigate the cause before running the roll thru, Steven.