Black bars on Samsung XL2370 external display with MBP 15" - help please

[fatgorilla]

Hello everyone,

I have a MacBook Pro 15" and my father has 17", both 2007 model.

I bought a new Samsung XL2370 external monitor (1920 x 1080) for my notebook. When I connect it to the 17" model, it works fine and gives me the full picture.

However, when I connect it to my 15" MBP, even at 1920 x 1080, the display gets cropped on two sides with black bars.

If I change the resolution to 1680 x 1050, then the whole screen is filled. But if I put it to 1920 x 1080, this happens.

What am I doing wrong ?

Many thanks for your help

 

[lixuelai]

Are you setting it to mirror or to extend your desktop?

 

[fatgorilla]

I'm having it mirrored on both computers. (I have tried setting up as extended monitors but in vain).