I've been experiencing some issues with undeveloped specks on my negatives. I am now considering that it is due to specks of something getting on my negative. I have a Hasselblad 500 c/m and I notice that the "foam" backing on the blinds of the auxiliary shutter appear worn. When I touch it with my finger, black rubs off on my skin. I am wondering if when the auxiliary shutter closes, some of this deteriorating foam is getting stuck on my negatives. Does this sound possible? If I want to replace this foam, what would I do? I am not even sure of the function of it since it is just on the back of the blinds. They look worn, cracked and some of it comes off easily. I am very frustrated since a roll I just developed has clear specks on them, and will print black. I don't think it is my development. Thanks for any advice.