Bruce,
FCP is pretty rubbish when it comes to management of video memory, you probably got something like this:
“Can’t render at the requested size and depth”
There are two ways round this which I have to give Gabriele at Noise Industries the credit for:-
1) Save your project, quit and re-launch Final Cut Pro. More often than not, Final Cut Pro will render the sequence on a fresh start.
2) Make sure that you are rendering in 8-bit YUV:
– Open the Sequence Settings window and switch to the Video Processing tab
– Select the “Render in 8-bit YUV” option
Hope that helps
Peter