I have 5 Polaroid holders and I have given up on all but the 545i's. They seem to give me the best luck because they have 2 'clips', not one. And on note of the film sticking, I know I'd posted a video showing how to take a polaroid sheet into the darkroom (or changing tent), disassemble, unstick the film from the envelope sleeve, reassemble and use. I have a box of T55 that I'd almost thrown out and i'm going to give it a go and see if I can salvage!