Aha...I finally rememebered where I have seen this, those look like emulsion scratches caused by the felt on the cartridge. Usually a piece of dirt gets caught in the felt and when you rewind, specially at high speed the dirt scratches the emulsion.
You can tell because it is intermitent but it is on a straight line. Of course, this happens right down the middle of the roll, if it was at the edge then it would not be the curse of the photo Gods....:P