Thank you David, the project was set up correctly using all the standard proceedures, I am an experienced editor and I’ve cut and pasted seuqnces from one timeline to another thousands of times but thev’e always be re-create as the original was, appart from this time, this isn’t an aspect ratio change or anything like that. There were some captions on a clour background and it’s re-sized the back ground too. It’s very eratic behaiour!