Helli (a member in the forum) posted the fix for this bug in the forum 10 months ago for version 2.1 - this should be added to the list of bugs/defects for the next release:
Add in wp-admin\export.php:
<excerpt:encoded><![CDATA[<?php echo $post->post_excerpt ?>]]></excerpt:encoded>
above:
<content:encoded><![CDATA[<?php echo $post->post_content ?>]]></content:encoded>
and in wp-admin\import\wordpress.php:
below:
$post_author = $this->get_tag( $post, 'dc:creator' );
place:
$post_excerpt = $this->get_tag( $post, 'excerpt:encoded' );
$post_excerpt = str_replace(array ('<![CDATA, ?]>'), , $post_excerpt);
$post_excerpt = preg_replace('|<(/?[A-Z]+)|e', "'<' . strtolower('$1')", $post_excerpt);
$post_excerpt = str_replace('<br>', '<br />', $post_excerpt);
$post_excerpt = str_replace('<hr>', '<hr />', $post_excerpt);
(above this line)
$post_content = $this->get_tag( $post, 'content:encoded' );
