[mplayer] Subtitle in the black space

[CrashRay]

Hi,
I install mplayer with macports with this :

sudo port install MPlayer +caca +darwin_8 +darwin_powerpc +dts +dv +dvdread +faac +fontconfig +freetype +gif +macosx +real +sdl +theora +twolame +xvid +x264

I read mkv file with crop video. I don't have black band. But when i use fullscreen, the black band appears.
But my subtitle are on the bottom of the video but not of the bottom of my screen. (Example)
When i put in my config file this :

ass=yes
ass-use-margins=yes
ass-bottom-margin=100
spualign=2
subalign=2

I have this screenshot. It's ok but if i read another format than 16/9, i have this instead of this.
Do you know a solution ?

Thanks