stop scroll image left on browser resizing

[Michael.A]

when i resizing my browser my image scroll to the left how can i stop that

here is my css

.c4l_body_top {
-moz-background-clip:border;
-moz-background-inline-policy:continuous;
-moz-background-origin:padding;
background:transparent url(images/coderz-st/misc/top.png) no-repeat scroll center center;
height:26px;
margin:0 auto;
}

here is a screenshot on full browner size



here is a screenshot when i width down the size of the browser !



live view: http://coderz4life.com/coderz/forum.php?styleid=46