trouble with scanned images and adjustment layers

Something I can't explain has cropped up. Importing new images from a Canon film scanner produces the seemingly correct .psd file, but I am unable to open any adjustment layers on these files. The selections are grayed out. Old scanned images from the same scanner and digital files from cameras can be manipulated fine with adjustment layers opened. This is a brand new problem and I can't figure out what the solution is. Any help please?! Using 7.01.

You're probably now scanning at 16-bit per channel, and were before at 8-bit.

I don't have a Canon scanner but the following may be your problem.

Is your film scanner scanning in 16-bit mode? If so, layers are not available in 16-bit mode. Convert your file to 8-bit and layers will be available.

Jake