FCP Video export/sync problems. HELP!

Hi,

So i am using FCP 7.0.3. I have used it a fair bit.

However recently i am trying to re-cut an edit which my brother shot to make it shorter and edit out the less nice shots so i can upload it to a new website.

I editied, the already exported file, which was all fine. Then i watched back the finalised exported file and the video is completely out of sync with what it was showing me in the fcp playback viewer. Suprisinngly diffiucult to describe but basically its like the video file has a delay after it is exported and shows completely different shots to the ones i chose and it was showing in the edit timeline. I have no idea what to do, anyone had this before? Anything i can do about it? Obviously the first section of the video is fine as it plays from the start as its the original but after the first chunk i cut out and there after all the clips are different shots to those that it was showing in the edit...hope you understand.

Any help would be greatly appreciated.

Cheers

Toby