adding to Bryce’s post, check the level of your blacks coming in to FCP. If your blacks are at 7.5IRE then setup is not being removed before your capture and you should remove it in FCP. The only time setup should even be an issue is when dealing with analog formats so if you are exporting to DVD, Digibeta, HD then your blacks should be at zero. Setup will then be added by the deck or dvd player on playback. It sounds like your footage has setup and then setup is being added again on playback.