import nextgen featured images messes up description with dashes and lowercase

Hi All
“import nextgen featured images messes up description with dashes and lowercase”

SO : want this: Extra beschrijving bla die Bla.
Creates this from import: extra-beschrijving-bla-die-Bla.

When targeting a featured image in a post/page or custom type page, from nextgen gallery the description has been altered by changing the first character into lowercase and replacing whitespaces into dashes…
Any suggestions to avoid this?

function the_post_thumbnail_description() {
  global $post;

  $thumbnail_id    = get_post_thumbnail_id($post->ID);
  $thumbnail_image = get_posts(array('p' => $thumbnail_id, 'post_type' => 'attachment'));

  if ($thumbnail_image && isset($thumbnail_image[0])) {
	echo ''.$thumbnail_image[0]->post_content.'';
  }
}

// nextgen, gallery, import, featured, image, images, description, alt, meta, title, caps, dash