I recorded 2 videos yesterday and one of them won't playback on my phone. The preview thumb for the video is a tiny icon of a rolling hill w/ a sun over it and the p.i.t.a. exclamation point. While the other video is fine with a normal preview thumb. I imported both to my pc thinking I could play with it there but no look. What happened and how could it (hopefully) be rectified? Thanks for any & all help!