I'll take a stab at this. I could be completely wrong though...(posted 8318 days ago)Could film curl be due to the emulsion and base acetate drying at different rates? Or perhaps it is the nature of the emulsion side to shrink a little as it dries?
Also, take a look at your environment. Did you recently turned on the heater in the house? Is the air drier than usual? Hotter? Colder? How about the humidity? I have a hunch that these all play factors.