Can you try going into your Sequence Settings, from there uncheck "Composite in Linear Color" Let us know if the outcome is better. If not, can you provide more details about your hardware and expect steps to reproduce the issue.
I already automatically uncheck that. With it checked dissolves start and end to abruptly.
I'm on a mac pro running Mac OSX 10.9.4 with ATI Radeon HD 5870 video.
It can be replicated on any timeline, with any type of clip exported to prores444. The same timelines/clips exported to prores422 are fine.
Can you run the Mercury Playback Engine in Software Only mode? Or is it already set that way?
It is already set to software only.
Can you enable the Mercury Playback Engine (OpenCL), or does your ATI card have less than 768MB VRAM? (there are two versions of the 5870).
Ok, I enabled it and it seems to have corrected the issue. I guess I have to remember to enable it before rendering, because while editing performance is greatly reduced when it is enabled. Thanks for your help.