I just got this defect on the image after developing. I used Xtol 1+1. The thing is that other films from the same batch of Xtol (same method) came out perfect. Gives me the impression that it's related to development but can it be the film ? Otherwise for me it's difficult to explain. And if it's the film, does one know what can be the source of the problem. It's not old film and it's from a good brand (Rollei).