Have some videos, am able to move them to the Playbook via the DM. Yet In the DM, they show up with a "!" in an orange box, in each video. Videos play ok on the Playbook, and have a preview image on the Playbook, yet in DM... that "!".
How can I get DM to put a preview image into the video screen, on the PC? File extension? File format? Something else?