Hi,
I wrote a patch for the ScaleVideo implementation in the dvbhddevice, for keeping the actual aspect ratio of the video material when scaling. It was tested by users at vdr-portal.de which also reported the distortions (I don't own such a device), and they said it works [1]. You can test it with the nOpacity skin and/or with the upcoming yaepghd-0.0.4 plugin [2].
Regards, Lucian
[1] http://www.vdr-portal.de/board1-news/board2-vdr-news/p1137059-announce-nopac... [2] http://sourceforge.net/projects/vdryaepghd/files/