Oliver said:

The form hangs after submit (SMTP)

In case you're using the SMTP feature:

• This requires a WP release coming with the phpmailer feature, check for class-phpmailer.php & class-smtp.php in wp-include/
• Due to a known WP bug (even still in 2.2.2), make sure you create a copy of class-smtp.php and rename to class.smtp.php
• Due to limitations on the phpmailer end, there is no support for SSL or TLS

General:

• For better trouble shooting, get a copy of Firefox & Firebug, which will allow you to see at-runtime all communication going back and forth as well as error messages (Console view).
• Submit form and record the error (click on Post / response)

My form still does not submit even though i have changed the setting