Try this:
<div id="respond">
<?php
if (!empty($_SERVER['SCRIPT_FILENAME']) && 'comments.php' == basename($_SERVER['SCRIPT_FILENAME']))
die ('Please do not load this page directly. Thanks!');
if ( post_password_required() ) { ?>
This post is password protected. Enter the password to view comments.
<?php
return;
}
?>
<?php if ( have_comments() ) : ?>
<h2 id="comments"><?php comments_number('No comments', 'One comment', '% Comments' );?></h2>
<div class="navigation">
<div class="next-posts"><?php previous_comments_link() ?></div>
<div class="prev-posts"><?php next_comments_link() ?></div>
</div>
<ol class="commentlist">
<?php wp_list_comments(); ?>
</ol>
<div class="navigation">
<div class="next-posts"><?php previous_comments_link() ?></div>
<div class="prev-posts"><?php next_comments_link() ?></div>
</div>
<?php else : // this is displayed if there are no comments so far ?>
<?php if ( comments_open() ) : ?>
<!-- If comments are open, but there are no comments. -->
<?php else : // comments are closed ?>
<p>Comments are closed.</p>
<?php endif; ?>
<?php endif; ?>
<?php if ( comments_open() ) : ?>
<h2><?php comment_form_title( 'Leave an reply', 'Leave a reply in %s' ); ?></h2>
<div class="cancel-comment-reply">
<?php cancel_comment_reply_link(); ?>
</div>
<?php if ( get_option('comment_registration') && !is_user_logged_in() ) : ?>
<p>You must be <a href="<?php echo wp_login_url( get_permalink() ); ?>">logged in</a> to post a comment.</p>
<?php else : ?>
<br class="c" />
<form action="<?php echo get_option('siteurl'); ?>/wp-comments-post.php" method="post" id="commentform">
<?php if ( is_user_logged_in() ) : ?>
<p>Logged as <a href="<?php echo get_option('siteurl'); ?>/wp-admin/profile.php"><?php echo $user_identity; ?></a>. <a href="<?php echo wp_logout_url(get_permalink()); ?>" title="Log out of this account">Log out »</a></p>
<?php else : ?>
<div>
<input type="text" value="Name" onblur="if (this.value == '') {this.value = 'Name';}" onfocus="if (this.value == 'Name') {this.value = '';}" name="author" id="author" size="22" tabindex="1" <?php if ($req) echo "aria-required='true'"; ?> />
</div>
<div>
<input type="text" value="Email" onblur="if (this.value == '') {this.value = 'Email';}" onfocus="if (this.value == 'Email') {this.value = '';}" name="email" id="email" size="22" tabindex="2" <?php if ($req) echo "aria-required='true'"; ?> />
</div>
<div>
<input type="text" value="Website" onblur="if (this.value == '') {this.value = 'Website';}" onfocus="if (this.value == 'Website') {this.value = '';}" name="url" id="url" size="22" tabindex="3" />
</div>
<?php endif; ?>
<br />
<div>
<textarea name="comment" id="comment" cols="58" rows="10" tabindex="4"></textarea>
</div>
<br class="c" />
<div>
<input name="submit" type="submit" id="submit" tabindex="5" value="Send" />
<?php comment_id_fields(); ?>
</div>
<?php do_action('comment_form', $post->ID); ?>
</form>
<?php endif; // If registration required and not logged in ?>
</div>
<?php endif; ?>
This may solve your issue in any Wordpress version since 3.1. Do not forget to put this code in your template folder (comments.php)