Taking a closer look at my recent contact sheets I noticed that the bottom of a lot of frames has the sprocket holes bleeding in. This seems to be exaggerated on fast film and overexposed shots, which probably makes sense. I see the same on slower films, like Ektar, but much less pronounced. On black and white film I can't seem to notice anything at all. These were all shot on an MP. Is this an issue with the camera?
Eric looks to me like a processing issue. If processed by hand it could be too much agitation or something to do with pouring the developer into the tank. If these are done by roller transport minilab then these comments are off base.
Check your negatives. Is it on the negative? It could be light-piping through the perforation when the contact sheet was made. It might not be there with proper masking...
Not even that; the light is so intense, that it hits the white photo paper, then reflects into the film through the perforation and then "Pipes" through the base. Not uncommon...