Ok, just tried a few things

Firstly tried to save a small section ready for use on a DVD, and the final saved file was the same as the preview, so its not just a preview thing

Second thing i tried was re-saving the files off the camera as an AVI file ( incase it made a difference ) but it didnt, still no good

However i saved the files as WMV files too, and tried that, and its smooth and perfect !

Only trouble is i dont want to save all the files as WMV and use them as its already lost a load of quality before i even start !

So maybe its just not coping with the higer quality ?

I really need to try and find another editing programme that can do the type of editing i need, but not seen one yet