Figures...I go on a trip out east and something like this happens. Here's the skinny: It shows up on about 50% of the shots. This is one of the worst, others are faint and I can burn/spot them in while printing so they're salvageable for the most part. I developed these with 13 other rolls of film at the same time and it ONLY showed up on the two rolls of FP4 125 film that I load in my Leica M4-P. So, I suspect camera. I have a sync plug busted out that I taped up and tape is slowly peeling, but this "leak" isn't hitting the edge of the frame -it's only inside the picture. This leads me to believe it's a sticky/erratic shutter movement or bounce, but it's not a super clean line. I looked at the curtains and they seem alright, but I think there was some patching going on at some point or something spilled around the spot where this is showing up. But since it happens for about 8 frames in a row, then skips 8, then another 4, then clean for 6, I don't think it's the curtains. Thoughts? Something on the shutter curtain track? Thought I would ask and explore myself before I send it in. The thing that stumps me the most is not the line in the photo you see, but in a blank shot, that has a "light leak" type of look to it. It likely fired in my bag, which would indicate this isn't a shutter issue. Not sure what to think at this point and any help would be great. Thanks in advance!