add custom string in tag title

Hi all,

in my header.php theme I have this code

<title><?php if(is_home() ) { bloginfo('name'); ?> | <?php bloginfo('description'); } ?>
		<?php if(is_single() || is_page() || is_archive() || is_tag() || is_category() ) { wp_title('',true); ?> | <?php bloginfo('name'); } ?>
		<?php if(is_404()) { ?> <?php echo $trns["404"]; ?> | <?php bloginfo('name'); } ?>
		<?php if(is_search()) { ?><?php echo $trns["seresults"]; ?> <?php echo wp_specialchars($s, 1); ?> | <?php bloginfo('name'); } ?>
	</title>

I use All in One SEO plugin and if I add a portion string last <title>, like:

<title>mystr<?php if(is_home() ) { bloginfo('name'); ?> | <?php bloginfo('description'); } ?>
		<?php............

when I refresh page this string portion is not printed