Hello long time....some people are getting troubles loggin off from the store.
First remember this:
logoff.php - first change yourdomain.com to your websites domain. Make sure you have the '.' before it.
FIND:
$cart->reset();
ADD AFTER:
//Facebook Connect
include 'includes/classes/facebook.php';
include_once "fbconnect.php";
setcookie('fbs_'.$facebook->getAppId(), '', time()-100, '/', '.yourdomain.com');
Second if the customer wants to logoff completely, he has to do it, from FB and from your store.
find the first </table></td>
add before that
<tr>
<td><?php echo tep_draw_separator('pixel_trans.gif', '100%', '10'); ?></td>
</tr>
<tr>
<td class="main"><?php echo TEXT_MAIN; ?></td>
</tr>
<tr>
<td><?php echo tep_draw_separator('pixel_trans.gif', '100%', '10'); ?></td>
</tr>
<tr>
<td class="main"><?php echo TEXT_FB; ?></td> <?php //FACEBOOK LOGOFF LITERATURE AND BUTTON ?>
</tr>
<tr>
<td><?php echo tep_draw_separator('pixel_trans.gif', '100%', '10'); ?></td>
</tr>
<tr>
<td><a target="_blank" href="http://m.facebook.com/logout.php" onclick="FB.Connect.logout(function() { reload(); }); return false;" ><img id="fb_logout_image" src="http://static.ak.fbcdn.net/images/fbconnect/logout-buttons/logout_small.gif" alt="Connect"/></a> </td>
</tr>
EASY!