I neglected to read the above note from hermie54 before posting my last response. While ProRes422 indeed is used for editing, it's also been long recommended to me as the preferred .mov choice for a FCP X Master file. I've been doing so for years and the AVCHD discs I've burned always are excellent. So it does, in fact, "work" with earlier versions of Toast. When FCP "Share to disc" is working, I usually let it do the job. But occasionally, usually after an IOS or FCP software update, it breaks (always near deadline) and I fall back on Toast 14. As previously mentioned, 14 Pro still works with ProRes422 .mov files from FCP but 17 currently does not. My FCP AVCHD discs are projected on a large screen before an audience of 100 or so and I want all the resolution I reasonably can get. That's why I've always gone with ProRes422. I also burn additional AVCHDs and standard DVDs for very limited distribution. However, I'm thinking now that I'll simply project my original Master .mov file via a laptop and hope Toast 17 gets "fixed" or my copy of Toast 14 continue to hang in there for disc production.