Saving problems

Hi,

I have a problem with saving data from a cloneable group.
I have the following code;

/**
			 * Tab: Keuze buttons
			 */
			array(
				'id' => 'buttons',
				'clone' => true,
				'type' => 'group',
				'max_clone' => 3,
				'tab' => 'buttons',
				'fields' => array(
					array(
						'name' => 'Titel',
						'desc' => '',
						'id' => 'button_title',
						'type' => 'text',
						'size' => 50
					),
					array(
						'name' => 'Link',
						'desc' => 'Selecteer de pagina die moet worden weergegeven.',
						'id' => 'button_link',
						'type' => 'post',
						'post_type' => 'page',
						'field_type' => 'select_advanced',
						'placeholder' => 'Selecteer een pagina',
						'query_args' => array(
							'post_status' => 'publish',
							'posts_per_page' => - 1,
						),
					),
				)
			),

When saving the page, the value of 'button_link' is stored in the database. 'button_text' is not saved. I tested this with the following code after all fields are filled in the WP admin;

$buttons = rwmb_meta('buttons', null, get_option('page_on_front'));
						foreach($buttons as $button){
							echo '<a href="'. get_permalink($button['button_link']) .'"><span>'. $button['button_title'] .'</span></a>';
						}

With this result;
Array ( [button_link] => 206 ) Array ( [button_link] => 271 ) Array ( [button_link] => 215 )