[Plugin: WP-PageNavi] Works only on first 5 pages.

Pagenavi works perfect when selecting page number 1 to 5 from my homepage.

However page 6 onwards and “Last” doesn’t seem to work.
(Gives me a 404 error)

Archive.php
<?php if(function_exists(‘wp_pagenavi’)) { wp_pagenavi(); }
else { ?>

<div class=”right”><?php next_posts_link(‘Next Page »’) ?></div>
<div class=”left”><?php previous_posts_link(‘« Previous Page’) ?></div>
<?php } ?>

Not sure why it works perfect till page 5 , but not from there onwards?

Thanks for any help

http://wordpress.org/extend/plugins/wp-pagenavi/