Header not centered in Chrome & Safari

Hi there,

I’m having some trouble with my header. It’s centered in FireFox, IE and Chrome on PC, but when viewed on a mobile device the header is floating to the left of the page.

Here are the pictures to show what I mean:

https://img15.picoodle.com/i594/farhank/1j72_1a3_u8tke.png
https://img13.picoodle.com/i594/farhank/1j72_436_u8tke.png

Here is the CSS code for the header:

#header {
	width: 980px;
	height: 117px;
	background: #FFFFFF url(images/header.jpg) no-repeat;
	margin:0px auto;

	margin-top: 10px;
	padding: 0 0 0 0; }

Any idea on how to fix this? I’m guessing it’s a simple CSS fix.

Thanks!