<apex:page showHeader="false" id="SiteTemplate" >
    <apex:stylesheet value="{!$Resource.StyleCSS2}"/>
     <div id="topgraybar"></div><center>
    
    <table border="0" cellpadding="4" cellspacing="4" bgcolor="#FFFFFF" width="900">
        <tr>
            <td>
                 <a href="http://www.yopup.com"><apex:image id="logo1" value="{!$Resource.STLogoNoTagLine}" width="272"/></a> 
             </td>
        </tr>
        <tr>
            <td>
                 <div id="nav">
                     <a class="nav_home" href="http://www.yopup.com"></a>
                     <a class="nav_about" href="http://www.yopup.com/about/"></a>
                     <a class="nav_sellers" href="http://www.yopup.com/sellers/"></a>
                     <a class="nav_buyers" href="http://www.yopup.com/buyers/"></a>
                     <a class="nav_partners" href="http://www.yopup.com/partners/"></a>
                     <a class="nav_community" href="http://www.yopup.com/community"></a>
              <!--       
                     <a class="nav_exchange" href="http://yopup.force.com/Ex/apex/categories"></a>
               -->      
                     <a class="nav_login" href="http://yopup.force.com/Ex/apex/sitelogin"></a>
                 </div>
                 
                  <div id="green_hr"><img src="http://dev.yopup.com/images/x.gif" height="1" width="1" alt="" border="0" /></div> 
            </td>
        </tr>
        <tr>
            <td>
               
                <apex:insert name="body"/>
            </td>
           </tr>
    </table></center>

</apex:page>

 I deployed a visualforcepage into sandbox, everything worked fine no error messages or warning mesages. However when i deployed that same page into production i got this warning message: the element type "center" should be terminated by the matching end-tag "</center>" at line 10,  but when i refresh the page the warning sign goes away.also the positioning of a pageblocksection was centered instead of being in the left. also there is no center element in the visualforce code so i dont know where it got that warning message from. here is a code snipet of the template that is used for the page.