Are you rendering your multicam sequence? That will cause you to see just one clip. You will need to edit your sequence before you render it. Also do you have the Multicam enabled in your RT settings on your sequence? This also will cause you to see just 1 clip. We have been editing 5 camera shoots with Multicam for 3 years now and haven’t seen hardly any bugs since the last update to FCP6. If you are having to render your sequence, your computer or drives may not be fast enough or your footage may not be supported. What’s your setup and what codec are you using?