HELP! (Part 2 of question about what might cause this)

Wouldn't a leak in the camera back affect all negs?. It didn't seem to on my roll and I think that the OP is saying that only some negs( the end ones) are affected on his.

I'd prefer it was the back because there is a cure for that but with loose rolls, well, it's back to what needs to change and I and maybe the OP are lost as to what to do about it.

pentaxuser

Thanks all for your suggestions. I have some initial suspicions about the seals on my film back, although I had replaced them all. Again, the mystery is its sporadic nature (not every time) and its position at the end of the roll.

Because I have all the materials, I will start with the replacement of the light seals again. As dark slide trap is new, I will simply inspect it. Then, I will try another test roll and see what happens. That will (hopefully) at least remove the spectre of a light leak.

After some reflection of your comments, I should note too that these are the last few rolls of a box of 120 FP4+ rolls I bought a few years back (during the initial Ilford is disappearing scare). I am also getting suspicious, given the shape, size and position appearance of this occasional problem, if something might be amiss there too (but it is my last hypothesis too).

Thanks again to all for your suggestions.