moodle-1.9-user table for authentication?

I failed getting the plugin running with the moodle user table 🙁

WP version: 3.2.1
Moodle version: 1.9.12

• All external db settings are correct (‘dbtype’, ‘dbhost’, ‘dbname’, ‘dbuser’, ‘dbpass’ from the moodle config.php)
• the usertable is set to ‘mdl_user’ (standard settings from a moodle-installation)
• encryption method: I’ve tried MD5 and SHA1 as well as ‘other’ with the additional hash code $password2 = md5($password.’salt_phrase_from_my_moodle-config.php’);

found the following articles/forum posts, but it’s still not working 🙁
http://jasontbedell.com/how-to-authenticate-users-from-moodle-into-wordpress-mu
http://moodle.org/mod/forum/discuss.php?d=148385
http://moodle.org/mod/forum/discuss.php?d=64452

Does anyone solved this or a similar problem?

Thanks,
Martin