I have converted an EOS5DMarkII clip with MPEGStreamclip to AppleProRes.
Then I have import the clip in FCP. The settings for the sequence have been adopted to the settings of the clip. I have followed the tutorial of RE:Vision Effects on how to do slowmotion using the twixtor plugin in FCP.
In the rendered clip I have the problem, that 5 frames are rendered correctly in 10% slowmo an then 5 still frames are following, than 5 correct ones, and than 5 stills again.
I have found some posts, whiche are explaining this problem with a framerate issue. But in the FCP twixtor plugin there are no settings for the frame rate. The only thing that I can do is to set the sequence setting same as the clip setting.