Opa, valeu por responder!!!
Então, tem som sim, aparentemente roda o video na boa, só não aparece nada no lugar da imagem... muito estranho mesmo...
Acabei de executar ele pelo terminal e a saida é essa:
juninho@juninho-ubuntu:/media/disk/movies/Snatch$ mplayer Snatch\ cd1.avi
MPlayer 1.0rc2-4.2.3 (C) 2000-2007 MPlayer Team
CPU: Intel(R) Celeron(R) CPU 2.40GHz (Family: 15, Model: 2, Stepping: 9)
CPUflags: MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.
Playing Snatch cd1.avi.
AVI file format detected.
[aviheader] Video stream found, -vid 0
[aviheader] Audio stream found, -aid 1
VIDEO: [XVID] 720x384 12bpp 25.000 fps 1453.7 kbps (177.5 kbyte/s)
SUB: Detected subtitle file format: subviewer
SUB: Read 789 subtitles.
SUB: Adjusted 6 subtitle(s).
SUB: Added subtitle file (1): ./Snatch cd1.srt
xscreensaver_disable: Could not find XScreenSaver window.
GNOME screensaver disabled
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg MPEG-4)
==========================================================================
==========================================================================
Forced audio codec: mad
Opening audio decoder: [liba52] AC3 decoding with liba52
Using SSE optimized IMDCT transform
Using MMX optimized resampler
AUDIO: 48000 Hz, 2 ch, s16le, 448.0 kbit/29.17% (ratio: 56000->192000)
Selected audio codec: [a52] afm: liba52 (AC3-liba52)
==========================================================================
AO: [pulse] 48000Hz 2ch s16le (2 bytes per sample)
Starting playback...
VDec: vo config request - 720 x 384 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.88:1 - prescaling to correct movie aspect.
VO: [xv] 720x384 => 720x384 Planar YV12
GNOME screensaver enabled.000 ct: 0.000 619/619 24% 2% 5.0% 29 0
Exiting... (Quit)
Se você conseguir identificar algum erro, por favor, me fala...
Muito obrigado!!!