Comment 2 for bug 236882

Thanks for your instant reply. Relevant packages I've got installed are

 - libdvdnav4 (0.1.10-0.2)
 - libdvdread3 (0.9.7-8ubuntu1)
 - libdvdcss2 (1.2.9-2medibuntu4)

Should I proof the installation of other packages?

Anyway, the error occurs also while reading the installation-CD's. Booting is possible, but then the error described above occurs. I also tried different media, which are all working in other computers.