LPH2005 on "wp_set_auth_cookie, external user logs into WP but cannot publish"

Hello,

Ever since 4.0 beta 2, WP turned on the feature for tying cookies and sessions together. Now plugin code that used to work for logging in an external user fails to allow the user (with correct permissions / roles ) to publish a post. The user can post a comment but cannot publish a WP post or page.

The error returned is "are you sure you want to do this?"

Code:

$visitor = $XF->visitor;
$user_ID = $visitor->get( 'user_id' );
wp_set_auth_cookie( $user_ID, 0, 0 );

Again, this code worked fine for years with previous versions but stopped with 4.0 beta 2 release. The user is logged into WP. It is the publish a post or page that fails.

Any suggestions on how to re-write the code?

Is this a problem in wp_verify_nonce?