Has this problem still not been solved for anyone? I am running Media Composer 8.4 on an iMac with OS 10.10.5
I use a second monitor (Dell) and when I move the composer window over to the second monitor, the problem goes away. Changing resolution size on the iMac doesn’t appear to help anything. This is the strangest problem I’ve ever seen on an NLE. So unless I want my windows to live on the second monitor (not as good of a display), I’m stuck with the image zooming in to the bottom left hand corner of the frame.
Interestingly, this only happens when parked at either the head or tail of a clip. Anyone else experiencing that little gem?