While resizing,1/3 of the picture dissappears

[Beyaz]

Hi;

There is no problem when watching the movies in its original size but when i try to resize or to make it full screen 1/3 of the picture dissappears from below. There is no sound or picture quality problem. I've tried to reinstall all codecs but same problem occured. I've tried Radlight,Bsplayer and WMP but all are same.

Can Anyone help me!

Thanks..