most common: buggy audio driver! - try to use different drivers, try ALSA 0.9 OSS emulation with -ao oss, also try -ao sdl, sometimes it helps. If your file plays fine with -nosound, then you can be sure it's sound card (driver) problem.
audio buffer problems (buffer size badly detected)
Workaround: MPlayer's -abs option
samplerate problems - maybe your card doesn't support the samplerate used in your files - try the resampling filter (-af resample=...)
slow machine (CPU or VGA)
try with -vo null, if it plays well, then you have slow VGA card/driver
Workaround: buy a faster card or read this documentation about how to speed up
Also try -framedrop
-ni or -nobps option (for non-interleaved or bad files)
-mc 0(required for files with badly interleaved VBR audio)
-delay or +/- keys at runtime to adjust delay
If none of these help, please upload the file, we'll check (and fix).
your sound card doesn't support 48kHz playback
Workaround: buy a better sound card... or try to decrease fps by 10% (use -fps 27 for a 30fps movie) or use the resample filter
slow machine(if A-V is not around 0, and the last number in the status line increasing)
your file uses an unsupported audio codec
read the documentation and help us adding support for it
your file uses an unsupported video codec
Workaround: read the documentation and help us adding support for it
auto-selected codec can't decode the file, try to select another using -vc or -vfm options
you try to play DivX 3.x file with OpenDivX decoder or XviD (-vc odivx) - install DivX4Linux and recompile player
First note: options -fs -vm and -zoom are just recommendations, not (yet) supported by all drivers. So it isn't a bug if it doesn't work. Only a few driver supports scaling/zooming, don't expect this from x11 or dga.
x11 driver: sorry, it can't be fixed now
xv driver: use -double option
Green image using mga_vid (-vo mga / -vo xmga).
mga_vid misdetected your card's RAM amount, reload it using mga_ram_size option