after i got much help with my light leaking polaroid-back, i'm here again -with a leaky filmback... it's a version I (not the RZ67 II) back and i already replaced the old gooey lightseals with new ones, but now i have a lightleak on pretty much every frame of a roll. varying in intensity, but always vertically across the whole negative, always straight from edge to edge of the negative. did i screw up installing the new lightseals or could it be the darkslide seal? i didn't replace the velvet darkslide cover, but disassembled the back and had a look, and it had good tension and seemd fine. so - anyone familiar with this kind of leak, or any other tips on locating the problem and / or fixing it? very much appreciated!