Thanks for the tip!

Carrara has never played well with Quicktime on Mac. Glad to hear there is a solution. Plus in my experience, when when rendering to QT, each consecutive frame takes longer while it recompresses. I don't know if Caffeine fixes that too.

I've always rendered to sequenced images to avoid issues and allow for other post processes in 3rd party software.

None of the other animation software I use ever lets the OS sleep while rendering, only Carrara. Neat-o. Always had to go to preferences and disable sleep during rendering. But everything seems to have certain pathologies.