Try using a loopcounter based on the post number count – provides for more flexibility
<?php if (have_posts()) : ?>
<?php $count = 0; ?>
<?php while (have_posts()) : the_post(); ?>
<?php $count++; ?>
// if you are in your first post
<?php if ($count == 1) : ?>
// do whatever you want to display your posts *assuming you want a featured top level*
<?php elseif ( in_array($count, array( 2,3,4,5 ) )) : ?>
// do whatever you want to display your posts
<?php elseif ($count == 6 ) : ?>
// do whatever you want to display your posts - this is probably the middle guy on a 3x3 grid with a featured 1st post
<?php elseif ( in_array($count, array( 7,8,9,10 ) )) : ?>
<?php else : ?>
<?php endif; ?>
<?php endwhile; ?>
<?php else : ?>
<?php endif; ?>