Search bar ‘stretch’?

look in your theme’s `style.css for this:

#header #search_menu { height: 90px; width: 475px; }

#header #search_menu #search { width: 400px; padding: 40px 0 0 2px; }

#menu { width: 400px; float: center; margin: 10px 0 0 2px; list-style: none; font-weight: bold; font-family: Helvetica, Arial; text-transform: uppercase; }

#menu li { float: left; padding: 2px 0 3px 3px; margin: 1px 12px 0 0; line-height: 1.6em; font-size: 0.9em; }

#menu li a { padding: 0; text-decoration: none; color: #000; }

#menu li a:hover { padding: 0; background: #000; color: #fff; text-decoration: none; }

#menu li span { display: block; float: left; padding: 2px 5px 5px 5px; }

change values appropriately – back up file 1st

try to change the width here:
input.search_input { width:342px; border: 0; background: #fff url(images/bg/input.png) no-repeat; padding: 5px; color: #E0691A; font-weight: bold; margin: 0; float: left; }