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

https://vborg.vbsupport.ru/attachment.php?attachmentid=123366&stc=1&d=1288755013

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

https://vborg.vbsupport.ru/attachment.php?attachmentid=123367&stc=1&d=1288755013

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