Taxonomy array dropdown

Hi,

In my admin I would like to add a meta box with a dropdown list of all the custom taxonomies of my portfolio.

At this moment I’m using this code for the array:

$types_array = array();
$types = get_terms('portfolio-category');
$types_array[0] = 'Select all';
foreach($types as $type) {
	if (is_object($type) ) {
		$types_array[$type->term_id] = $type->name;
	}
}

Problem is that the dropdown menu isn’t displaying the categories, only the option “Select All”. So it’s empty…

To check if there was a bug in my metabox code, I’ve tested it with tags and pages, like this code:

$options_tags = array();
$options_tags_obj = get_tags();
foreach ( $options_tags_obj as $tag ) {
  $options_tags[$tag->term_id] = $tag->name;
}

And this code is working perfect, so there’s a bug in my array. But I’ve been trying for hours now… Somebody who can help me out? Thanks!