Hi Nick
Thanks for the reply.
Yes, looks to be a very similar issue. I stupidly did Capture Now and didn’t split the clips up so they are really quite large.
I was getting slipping on render and export (of sequences).
I used Compressor to transcode each original media file to an Apple ProRes format and reconnected the FCP bin clips to those new files.
Didn’t solve it completely as had to slip and slide many clips and edits to get them back to what I originally cut. But at least the render/export behaviour is now sorted and functioning as expected.
Lesson learnt.
Hate working with tape these days and, being so rare, you forget some of these little gotchas.
Cheers
Andrew