FCP audio sync problem...
 

This is probly a dumb question, but I'm having a lot of trouble understanding the linking between video and audio in a Final Cut timeline.

I just want to take a piece of video from the browser and replace something on the timeline with it. I want the audio to stay the same.

It seems that no matter what type of edit I use (insert, overwrite, paste, etc.) the audio goes out of sync by some random amount. It puts the little red box with + or - some time and if I listen the audio is indeed out of sync. This happens even if I put it on different tracks and "disconnect" the ones with the original video and audio.

I even tried deleting a whole piece of the timeline and putting in my clip, and then closing the audio back up with a Roll Edit but that makes it go out of sync again (and it's showing a through-edit that's in-sync on one side and out-of-sync on the other). At some point I somehow ended up making the audio start at the beginning of the file instead of the inpoint, so it was many minutes out of sync, and I had to revert my project back several versions.

I've only been using Final Cut for a week, and I'm totally baffled at how the audio sync works.

In Final Cut you can toggle between linked and unlinked video and audio. I believe the default key is apple-L to toggle between linking on or off, or you should see a little icon on the top right hand side of the timeline (one is snapping, the other is linking)

If it's green Audio is linked and thus will change with your video as you change your video. If the icon is not green linking is off and audio won't move with video.

If that red box does appear on a clip accidentally, you can actually just control click (right click) on the red box (you may need to zoom into the timeline a bit, or increase your track height) and it will give you a contextual menu that will allow you to automatically resync the audio as awell.

I think my project is corrupted or something, things are working in other projects but not this one...