WMC, WMP, VLC, etc... not the same!

[Myouh]

I've just noticed something for the first time...
I play my MPEG-2 video using Media Player Classic, then using Windows Media Player, then VLC Media Player, and it never plays the SAME !
the first plays the images faster than the last, and the other one (windows media player) is between the two. which means that the synchronization isn't the same for all those players.
in other words, my video is well synched if played by Windows media player, but a little off sync if played by VLC.
this is a huge problem... is this normal??
now I don't know what to sync my video to...
help...

(of course the difference is very slight but still noticable)