you are creating a mess for yourself. here is one of your posts
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<h2><a href="http://yupyup.altervista.org/?p=50" rel="bookmark" title="Permanent Link to ARAYA">ARAYA</a></h2>
Jan 10th, 2011, <img src="http://yupyup.altervista.org/wp-content/themes/atahualpa353/images/icons/comment-gray.gif" alt="" />
<a href="http://yupyup.altervista.org/?p=50#respond" class="comments-link" title="Comment on ARAYA">Commenta</a>
<p>De Quincey was oppressed by debt for most of his adult life; along with his opium addiction, debt was one of the primary constraints of his existence. He pursued journalism as the one way available to him to pay his bills; and without financial need it is an open question how much writing <span style="color:#777"> → <a href="http://yupyup.altervista.org/?p=50">Read+ </a></span>[...]
<div id="post-50" class="post-50 post type-post hentry category-uncategorized">
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you are missing the closing </p>
you are missing a closing</div>
you have the content of the post before the <div> for the post
and who knows what else
Custom changes like this to the theme are really beyond the scope of the forum. If you are unsure about how to do detail customization and how php/css work, you might want to put a post in the Customization, Design, Programming...
section and see if you can hire some one to help you out.