Fullscreen Video dosnt show correctly

Ok i realy done know what forum this is under, have one both at the CE and this one.

But my guess is that people in this forum might know what im talking about.

Ive just change my monitor from a CRT to a LCD 16:10 monitor, and when i play movies either letterbox or 4:3 in short, any movie that brings thoes blacklines at the sides or top and buttom. Thies lines or edges, whatever they realy are called i dont know, but they show in a dark gray color insted of black. and at first i thought it was the light ratio, but then i noticed that when there is black in the movie its realy black and not at the same level as the bars around the movie.

If what i just wrote dosnt make sense please say so and ill explain it again in another way.