Hi Sam,
Are you ingesting this footage via the Media Browser? File based media simply must be imported there, not via File > Import or dragging footage into the Project panel. A lot of users are having issues with certain formats if they are not ingested correctly.
Is this a CC 2014.1 project, a CC 2014 project, or a CC 2014 project that was updated to CC 2014.1?
Can you try renaming the media files folder and reimporting via the Media Browser? You may have to relink.
Thanks,
Kevin
