Hi luckymushroom,
I hope, I may answer your question in English, my German is too bad.
I had the same problem with plugin version vdr-dvd 0.3.3. Now I use version
vdr-dvd0.3.4-rc6 and everything seems to be ok.
You can download it here: http://jausoft.com/Files/vdr/vdr-dvd/
Best regards Jan,
I use a52-dec -> 0.7.4
libdvdnav -> 0.1.9
libdvdcss -> 1.2.8