Custom post type’s get_permalink returns wrong url

Currently my permalink setting is /paper/%postname%/.

I am developing a plugin, so the following is done during the activation.

I am programatically adding a new custom-post-type called ‘meta’, like this (at ‘init’):

register_post_type( POST_TYPE,
  array(
  'labels' => array('menu_name' => 'meta'),
  'public' => true,
  'rewrite' => array('with_front'=>false,'slug'=>'meta','pages'=>false)
  )
);

Then in the activation I programatically added a meta post, and use get_permalink(). But I get the following url:

http://localhost/wordpress/paper/faq/

This url leads to the ‘not found’ page. The correct url should be:

http://localhost/wordpress/meta/faq/

In the admin meta post edit page, the displayed permalink is the correct http://localhost/wordpress/meta/faq

I also tried to flush_rewrite_rules(); before I call get_permalink(). But it didn’t work.

Does anyone have any idea?