Hi Colin,
Are you on Windows or Mac? Does this movie open at the correct size in QuickTime Player 7? What version of the DNxHD codecs do you have installed?
One of our developers is working on a number of codec-related issues at the moment so if this is a bug in mocha I will raise it with him.
Thanks,
J-P
John-Paul Smith | CEO | Imagineer Systems
http://www.imagineersystems.com