wp_insert_post strips characters

Hi im using wp_insert_post to automatically insert posts into WP

When i try to insert something with title like:
“Röyksopp” or “It´s So Hard” and so on…
WP just removes everything and keeps only characters before apostrof or “ö” like this: “R” or “It” and save it as title…
I dont know what to do..

my insert code:

$title = $artist.’ – ‘.$song;

$post[‘post_status’] = ‘publish’;
$post[‘post_type’] = ‘mptrojka’;
$post[‘post_title’] = $title;
$post[‘post_content’] = ”;
$post_id = wp_insert_post($post);
update_post_meta($post_id, ‘zdroj’, $host);
update_post_meta($post_id, ‘odkaz’, $url);
wp_set_object_terms( $post_id,$artist,’artist’ ,false);

Thanks