I'm having this exact same problem - it's incredibly, incredibly frustrating. I've tried uninstalling and reinstalling Capture, I've tried every option(exporting wavs, AIFs, etc.) I can think of and nothing works. Now I'm downloading the free version of Studio One just to see if that will work. For how much we spent on the mixer, specifically for recording - if I'd known how buggy it would be I would have gone with another option.