Video plays speed x 12 in PE2014 (audio normal)

Some of the video clips in my PE14 project are exposed in a strange way. The video track are running approx 12 times faster than normal - the video scene repeats again and again until the audio track ends. The audio plays normal and with normal speed. And there are differences between video clips captured the same day, with same length and with the same video camera.

Using win 10. Had no problems in my previous laptop. Videoclips runs normal in Win Media Player so it seems to be something wrong with PE14 setting, not OS-related.

Any explanations out there? Can settings in graphic or audio card cause this? Have tried to change different settings in audio card but it makes no difference. Have tried to render the video, restart project etc. without progress...