By default SharePoint 2010 Search Center site will not have the top navigation.
To add the top navigation to your SharePoint 2010 Search Enter Site, you need to copy from the v4.master the entire block of code starting
<div id=”s4-topheader2” class=”s4-pr s4-notdlg”> and to end of <dev> and past it in your SharePoint Search Center site where you want the top level navigation to reside
Copy the code from v4.master and past it in your SharePoint Search Center Site to display top level navigation to your site.
After pasting the code, you should see the top level navigation appear in your SharePoint 2010 Search Center Site