Post in Sidebar by categories

Hello.
I have this code in mi sidebar.php theme, and work fine just to 2.5 version.

<?php

if ( is_category(1) || in_category('1')) { $myposts = get_posts('numberposts=5&offset=1&category=1'); } else if ( is_category(3) || in_category('3')) { $myposts = get_posts('numberposts=5&offset=1&category=3'); }  else if ( is_category(4) || in_category('4')) { $myposts = get_posts('numberposts=5&offset=1&category=4'); }  else if ( is_category(5) || in_category('5')) { $myposts = get_posts('numberposts=5&offset=1&category=5'); }  else if ( is_category(6) || in_category('6')) { $myposts = get_posts('numberposts=5&offset=1&category=6'); }  else if ( is_category(8) || in_category('8')) { $myposts = get_posts('numberposts=5&offset=1&category=8'); }  else if ( is_category(9) || in_category('9')) { $myposts = get_posts('numberposts=5&offset=1&category=9'); }  else if ( is_category(7) || in_category('7')) { $myposts = get_posts('numberposts=5&offset=1&category=7'); }

 foreach($myposts as $post) :

 ?>

    <li><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></li>

 <?php endforeach; ?>

I need show in sidebar only the post of the selected category, and the same problem i have with single.php, page.php and browser.php, show only de last 10 post, and not the post of the selected categorie.
Thanks by your time.