lahell

Sorry, my bad. You must change this line:
$error_string = $result->get_error_message();
To this:
$error_string = $results->get_error_message();

wp_remote_get on line 428 returns an error after trying to contact the Bring Fraktguide API. I think wp_remote_get uses cURL. Is cURL installed on your web server?

Put the following code between line 428 and 429 in wp-e-commerce-bring-fraktguide.php. It should display more details about the error.

if ( is_wp_error($results) ) {
   $error_string = $result->get_error_message();
   echo '<div id="message" class="error"><p>' . $error_string . '</p></div>';
}

Try version 0.3. Works with WP 3.1.3 and WPeC 3.8.3. I will add installation instructions to a future release.