My negatives are very curved after drying, and I am certain that some of the scratches that I am seeing in the scans are a result of feeding excessively curled film into the scanner.
Also, I am going to modify my 5000ed to scan entire rolls of film at once, using the instructions here:
Nikon Coolscan Roll-Feeder Conversion
So, how can I flatten the entire roll (without cutting into smaller pieces)? Also, does the humidity affect the curling of the film when it dries (my house is currently quite dry).