Problem with flickering lines - Apple Prores


I have problem with a video encoded in Apple ProRes together with Kdenlive. The video clip has some kind of thick flickering lines, see screenshot: These noise lines appears when played in the Clip Monitor, in the Project Monitor as well as in the final rendered output.

This problem is only within Kdenlive, when playing the same video with e.g. mplayer the picture is without this noise

Could it be a codec problem? I see that mplayer use ffprores: "Selected video codec: [ffprores] vfm: ffmpeg (FFmpeg Apple ProRes)", but I'm not sure if Kdenlive uses the same? Or could there be any other reason?

I use Kdenlive Version 0.9.2 with KDE Development Platform 4.8.4 on Ubuntu 12.04.

Any help appreciated - thank you in advance!

Kind Regards,