Thanks for the response Walter 🙂
It’s definitely the same file, I’ve triple checked that and tried taking them out of FCP, restarting, putting them back in etc. I read that it’s a common problem when a video is changed from ntsc to pal that FCP misinterprets the metadata.
I’m afraid I don’t have the installation discs – it was a volume licence from my last job. But if there’s no other solution, I guess I’ll have to find me some discs!