Audio out os sync

I've created a project and it is out of sync with the audio and visual.

The strange thing is that the audio is out of sync at different parts each time I watch it. What is causing this and how do I fix it?

Thanks,

Jay

Sounds more like a playback issue. Verify by doing 3 exports and see how each comes out.

When you say it sounds like a playback issue what do you mean exactly? Surely playback is the only thing that matters isn't it?

It can be out of sync physically, or only in playback. If it is out of sync in different parts, that rules out physical issues. Set Playback to "Better Performance" and see if that helps.

Sorry to be a pain but how do I do that on final cut pro x?

Viewer menu, top right of Viewer, looks like a light switch.