problem with video playing on ifone 5s

Hi all. I am posting this on behalf of a friend who has got an ifone 5s but she can't speak English. I think she has got the latest ios installed. When she plays the videos she recorded with the camera, the video stops playing when she changes from landscape to portrate. She said that she didn't have this problem inicially and only recently she saw this behaviour. She said that if she tern off voice over she hasn't got this problem. So i hope somebody can help Nikos