And a further 2 years (almost!) on… i am having the same problem.
In my case i’m going from a 1080p film scan (some at 18fps, some at 24fps) to PAL output and it seems to be resulting in two black frames at every cut.
Did anyone stumble upon a solution/reason?
I’ll be trying to sort this out until it works, so will post my results in case any other FCP-newcomers like myself run into this.
Cheers, M