Are you playing quicktime files? That’s all cubase works with.
Cubase 5 had some issues playing back H264 quicktimes though (jittery). I don’t know if 6 does.
Open up the inspector in quicktime player and see what codec was used.
Can you help them further, by supplying a small segment of the file to analyse, via a Support Ticket in MySteinberg…? Posting here is NOT the route for SB Support.
Direct (Official) SB Support details are in the ‘sticky’ at top of the forum page.
AS far as I’m aware, Cubase has a problem with H264 even thought it plays back fine in Quicktime on the desktop (and in Logic). I posted about this just before the switch from the old forum.
I do a lot of work to picture and always have to convert the files to a different quicktime compression. I can’t remember which one, I think it’s mpeg4. I can check at the studio tomorrow.