This bug still exist, 10.10 cannot play dvd's stable. Does not matter what kinda drive, sata / pata, does not matter which player is used. Tested vlc, video-player and gnome-mplayer with this. Here you get a mplayer  debug from this issue. Movies are only played some minutes, then suddenly stops.

ERROR: mplayer: No such file or directory
Playing dvd://1.
ERROR: Failed to open LIRC support. You will not be able to use your remote control.
ERROR: libdvdread: Using libdvdcss version 1.2.10 for DVD access
ID_DVD_TITLES=7
ID_DVD_TITLE_1_CHAPTERS=36
ID_DVD_TITLE_1_ANGLES=1
ERROR: libdvdread: Can't seek to block 3214014
ID_DVD_TITLE_2_CHAPTERS=2
ERROR: libdvdread: Can't seek to block 3214014
ID_DVD_TITLE_2_ANGLES=1
ERROR: libdvdread: Invalid IFO for title 2 (VTS_02_0.IFO).
ID_DVD_TITLE_3_CHAPTERS=2
ERROR: libdvdread: Can't seek to block 3800091
ID_DVD_TITLE_3_ANGLES=1
ERROR: libdvdread: Can't seek to block 3800091
ID_DVD_TITLE_4_CHAPTERS=2
ERROR: libdvdread: Invalid IFO for title 3 (VTS_03_0.IFO).
ID_DVD_TITLE_4_ANGLES=1
ERROR: libdvdread: Can't seek to block 3214014
ID_DVD_TITLE_5_CHAPTERS=2
ERROR: libdvdread: DVDDiscId read returned 0 bytes, wanted 34816
ID_DVD_TITLE_5_ANGLES=1
ERROR: 
ID_DVD_TITLE_6_CHAPTERS=2
ERROR: libdvdread: Attempting to retrieve all CSS keys
ID_DVD_TITLE_6_ANGLES=1
ERROR: libdvdread: This can take a _long_ time, please be patient
ID_DVD_TITLE_7_CHAPTERS=1
ERROR: 
ID_DVD_TITLE_7_ANGLES=1
ERROR: libdvdread: Get key for /VIDEO_TS/VIDEO_TS.VOB at 0x0000013e
ID_DVD_TITLE_1_LENGTH=6876.360
ERROR: libdvdread: Elapsed time 0
ID_DVD_VOLUME_ID=DELTA_GOODREM
ERROR: libdvdread: Get key for /VIDEO_TS/VTS_01_0.VOB at 0x00000197
There are 7 titles on this DVD.
ERROR: libdvdread: Elapsed time 0
ID_DVD_CURRENT_TITLE=1
ERROR: libdvdread: Get key for /VIDEO_TS/VTS_01_1.VOB at 0x00027516
There are 1 angles in this DVD title.
ERROR: libdvdread: Elapsed time 0
audio stream: 0 format: ac3 (5.1) language: unknown aid: 128.
ERROR: libdvdread: Get key for /VIDEO_TS/VTS_02_0.VOB at 0x00310acf
ID_AUDIO_ID=128
ERROR: libdvdread: Elapsed time 0
audio stream: 1 format: ac3 (stereo) language: unknown aid: 129.
ERROR: libdvdread: Get key for /VIDEO_TS/VTS_02_1.VOB at 0x00319194
ID_AUDIO_ID=129
ERROR: libdvdread: Elapsed time 0
number of audio channels on disk: 2.
ERROR: libdvdread: Get key for /VIDEO_TS/VTS_03_0.VOB at 0x0039fc24
number of subtitles on disk: 0
ERROR: libdvdread: Elapsed time 0
CHAPTERS: 00:00:00,00:05:47,00:05:55,00:10:06,00:14:29,00:16:18,00:19:48,00:20:06,00:24:39,00:25:56,00:29:11,00:32:46,00:38:00,00:38:57,00:43:41,00:47:45,00:48:57,00:53:01,00:53:42,00:58:04,00:58:36,01:02:07,01:05:50,01:07:04,01:13:42,01:18:34,01:22:30,01:25:44,01:27:46,01:31:54,01:33:49,01:37:50,01:38:37,01:45:07,01:53:06,01:54:34,
ERROR: libdvdread: Get key for /VIDEO_TS/VTS_03_1.VOB at 0x0039fc2b
ID_VIDEO_ID=0
ERROR: libdvdread: Elapsed time 0
MPEG-PS file format detected.
ERROR: libdvdread: Found 3 VTS's
ID_AUDIO_ID=129
ERROR: libdvdread: Elapsed time 0
VIDEO:  MPEG2  720x576  (aspect 3)  25.000 fps  8600.0 kbps (1075.0 kbyte/s)
ERROR: open: No such file or directory
ID_FILENAME=dvd://1
ERROR: [MGA] Couldn't open: /dev/mga_vid
ID_DEMUXER=mpegps
ERROR: open: No such file or directory
ID_VIDEO_FORMAT=0x10000002
ERROR: [MGA] Couldn't open: /dev/mga_vid
ID_VIDEO_BITRATE=8600000
ERROR: [VO_TDFXFB] Can't open /dev/fb0: No such file or directory.
ID_VIDEO_WIDTH=720
ERROR: [VO_3DFX] Unable to open /dev/3dfx.
ID_VIDEO_HEIGHT=576
ID_VIDEO_FPS=25.000
ERROR: Couldn't open video filter 'ass'.
ID_VIDEO_ASPECT=0.0000
ERROR: ASS: cannot add video filter
ID_AUDIO_FORMAT=8192
ID_AUDIO_BITRATE=0
ID_AUDIO_RATE=0
ID_AUDIO_NCH=0
ID_START_TIME=0.11
ID_LENGTH=6876.36
ID_SEEKABLE=1
ID_CHAPTERS=36
Opening video filter: [screenshot]
ERROR: [ass] Init
==========================================================================
ERROR: [ass] Updating font cache
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffmpeg2] vfm: ffmpeg (FFmpeg MPEG-2)
==========================================================================
ID_VIDEO_CODEC=ffmpeg2
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 48000 Hz, 2 ch, s16le, 448.0 kbit/29.17% (ratio: 56000->192000)
ID_AUDIO_BITRATE=448000
ID_AUDIO_RATE=48000
ID_AUDIO_NCH=2
Selected audio codec: [ffac3] afm: ffmpeg (FFmpeg AC-3)
==========================================================================
[export] Exporting to file: /tmp/mplayer-af_exportbivdve
[export] Memory mapped to file: /tmp/mplayer-af_exportbivdve (0x7f78ed42f000)
[export] Exporting to file: /tmp/mplayer-af_exportbivdve
[export] Memory mapped to file: /tmp/mplayer-af_exportbivdve (0x7f78ed42f000)
AO: [pulse] 48000Hz 2ch s16le (2 bytes per sample)
[export] Exporting to file: /tmp/mplayer-af_exportbivdve
[export] Memory mapped to file: /tmp/mplayer-af_exportbivdve (0x7f793df63000)
[export] Exporting to file: /tmp/mplayer-af_exportbivdve
[export] Memory mapped to file: /tmp/mplayer-af_exportbivdve (0x7f793df63000)
ID_AUDIO_CODEC=ffac3
Starting playback...
ID_AUDIO_ID=128
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
ID_VIDEO_ASPECT=1.7778
[swscaler @ 0x7f79392fc620]BICUBIC scaler, from yuv420p to rgb24 using MMX2
VO: [vdpau] 720x576 => 1024x576 Planar YV12 
Resizing to 1024 x 576
current size = 0 x 0 
Changing window size to 1024 x 576 visible = 1
media size = 1024 x 576
media size = 1024 x 576
ERROR: [mpeg2video @ 0x7f7939f4a020]ac-tex damaged at 2 1
[mpeg2video @ 0x7f7939f4a020]concealing 1575 DC, 1575 AC, 1575 MV errors
ERROR: [mpeg2video @ 0x7f7939f4a020]Warning MVs not available
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
ERROR: [ac3 @ 0x7f7939f4a020]frame sync error
AUDIO: 48000 Hz, 2 ch, s16le, 448.0 kbit/29.17% (ratio: 56000->192000)
ID_AUDIO_BITRATE=448000
ID_AUDIO_RATE=48000
ID_AUDIO_NCH=2
Selected audio codec: [ffac3] afm: ffmpeg (FFmpeg AC-3)
==========================================================================
[export] Exporting to file: /tmp/mplayer-af_exportbivdve
[export] Memory mapped to file: /tmp/mplayer-af_exportbivdve (0x7f793df63000)
[export] Exporting to file: /tmp/mplayer-af_exportbivdve
[export] Memory mapped to file: /tmp/mplayer-af_exportbivdve (0x7f793df63000)
AO: [pulse] 48000Hz 2ch s16le (2 bytes per sample)
[export] Exporting to file: /tmp/mplayer-af_exportbivdve
[export] Memory mapped to file: /tmp/mplayer-af_exportbivdve (0x7f793df63000)
[export] Exporting to file: /tmp/mplayer-af_exportbivdve
[export] Memory mapped to file: /tmp/mplayer-af_exportbivdve (0x7f793df63000)
ID_AUDIO_TRACK=128
ID_AUDIO_TRACK=128
ERROR: Failed to get value of property 'sub_demux'.

ERROR: libdvdread: Can't seek to block 316100
ERROR: libdvdread: Can't seek to block 316100
ERROR: libdvdread: Can't seek to block 316100
ERROR: libdvdread: Can't seek to block 316100
ERROR: libdvdread: Can't seek to block 316100
ERROR: libdvdread: Can't seek to block 316100
ERROR: libdvdread: Can't seek to block 316100

ERROR: libdvdread: Can't seek to block 316100
Exiting... (End of file)
Thread completing
shutting down threadquery for dvd://1 since threaddata->done is TRUE