I understand that you may be reluctant to try this, however, I had the exact same problem last night with a two hour movie I just finished for a friend, tried to export from FCP using export using compressor and received the “failed” warning so I had to export a quicktime and import it into compressor. It works and I don’t hink it’s really a work around, think about it this way, let’s say another editor gave you the quicktime file to compress for him because he doens’t have DVD studio pro, this is the way you would have to get the file into compressor. Does this make sense? Sorry, but you might have to change your workflow.