Just to chime in — not with an answer, unfortunately, but only to report that I have exactly the same problem. I have done numerous tests, been very careful with all the settings, have tried many permutations of the settings experimentally, etc. All resulting in no joy. I cannot get DVCPRO 720 material (as ProRes or not, etc.) to do a round trip from FCP to AE and back without the gamma/color shift making the product unusable. This is not just one person’s isolated problem.