Your CSS for these divs is:
#outerWrapper #header {
background-color: #ffffff;
background-image: url(../siteassistpro_images/Logo1.jpg);
background-repeat: repeat-y;
color: #006;
font-size: 36px;
font-weight: bold;
width: 744px;
height: 80px;
line-height: normal;
padding: 15px 0px 0px 15px;
}
#outerWrapper #topNavigation {
background-image: ("../siteassistpro_images/Logo1.jpg");
background-position: bottom;
background-repeat: no-repeat;
color: #fff;
font-weight: bold;
width: 744px;
height: 31px;
padding: 0px 10px 0px 0px;
background-color: #AB4C34;
}
In the '#outerWrapper #header' CSS - you have added 15px padding to the left of the div. You should either remove this padding or reduce the width of the div by 15px to accommodate it.
In the '#outerWrapper #topNavigation' CSS - you have added 10px padding to the right of the div. You should either remove this padding or reduce the width of the div by 10px to accommodate it.