Sorry to hear about this. Is this happening with any specific media type or is it with all of them? Also, have you tried switching the Renderer to Mercury Playback Engine Software Only & checked if it's working properly?
I'm also encountering this. I don't do a done of sharpening so I haven't noticed it before, but there's definitely a noticeable shift to green using unsharp mask. It's pretty easily corrected, but annoying.