LG full HD LCD Monitor 1180 pix screen only goes to 750 pix running off PS3?

The PS3 says it is running at 1180 pix but the screen sys it is running at 750pix and it's a 1180 pix screen how to I get it to go full blast 1180 pix? It's an LG Flatron W2361V. How do I make it go full blast?