i'm using metabox 4.1.11.
when i'm registering this meta-box:
$meta_boxes[] = array(
'id' => 'projects',
'title' => 'Pin to project',
'pages' => array( 'post', 'event', 'designs', 'links' ,'images' ,'files' , 'videos' ),
'context' => 'side',
'priority' => 'low',
// List of meta fields
'fields' => array(
array(
'name' => 'project to pin',
'id' => "per-projects",
'type' => 'select',
'multiple' => true,
'options' => array(
'project 1' => 'project 1',
'project 2' => 'project 2',
'project 3' => 'project 3',
'project 4' => 'project 4'
)
)
)
);
