Hm. There could be, but it never happened before. Now that you mention it though, the sheet of paper came off the top of the stack, and maybe there are some pinholes in the black bag. Maybe I'll try a sheet from the center of the stack. The spots don't really correspond to each other between the two prints though.

Do those dark spots appear outside your normal working area ?
I'm not sure what you mean; my darkroom is a walk-in closet. There's nowhere else to go!