dvdcss fails in one machine and succeeds in another
My dvdbackup fails on my "media center" (running Debian stable with libdvdcss2:i386 1.4.0-1~local) when trying to copy "Le renard et l'enfant". It gives me output like the following:
libdvdread: Get key for /VIDEO_TS/VIDEO_TS.VOB at 0x00000163
libdvdread: Elapsed time 1
libdvdread: Get key for /VIDEO_TS/VTS_01_0.VOB at 0x0001b8a9
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_01_1.VOB at 0x000250b2
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_02_0.VOB at 0x001cda2c
libdvdread: Error cracking CSS key for /VIDEO_TS/VTS_02_0.VOB (0x001cda2c)
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_02_1.VOB at 0x001cdbb3
libdvdread: Error cracking CSS key for /VIDEO_TS/VTS_02_1.VOB (0x001cdbb3)!!
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_03_0.VOB at 0x001cdd5d
libdvdread: Error cracking CSS key for /VIDEO_TS/VTS_03_0.VOB (0x001cdd5d)
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_03_1.VOB at 0x001cde18
libdvdread: Error cracking CSS key for /VIDEO_TS/VTS_03_1.VOB (0x001cde18)!!
It always succeeds on the first few keys and then fails on subsequent ones, but the number of successful and unsuccessful ones aren't always the same.
The funny thing is that this is with a USB-connected DVD drive and if I plug that drive into my desktop (running the same Debian stable with the same library, except the amd64 version of it) dvdbackup reads the disk without any trouble.
What can I do to get more info about the source of the underlying failure?