https admin vs http site issue:
I spent a lot of time looking for a problem with our theme, but our issue turned out to be something entirely different. Maybe this post will help someone else.
If your setup runs SSL on the admin portion of your site, but the public-facing site is not secured, the password cookie isn’t being recognized. If you put the “s” in “http” on the page with the password and it works, you can solve this issue by rewriting the password form in your theme’s functions.php file like this:
add_filter( 'the_password_form', 'custom_password_form' );
function custom_password_form() {
$url = get_option('siteurl');
$url = preg_replace("/^http:/", "https:", $url);
global $post; $label = 'pwbox-'.( empty( $post->ID ) ? rand() : $post->ID ); $o = '<form class="protected-post-form" action="' . $url . '/wp-login.php?action=postpass" method="post">
' . __( "<h2>Enter password</h2>
<p>This content is password protected. To view it please enter the password below:</p>" ) . '
<label for="' . $label . '">' . __( "Password:" ) . ' </label><input name="post_password" id="' . $label . '" type="password" size="20" /><input type="submit" class="submit" name="Submit" value="' . esc_attr__( "Submit" ) . '" /> </form>
';
return $o;
}