Custom Post Type Category

I am using the code

add_filter("gform_post_data", "update_post_type", 10, 2);
function update_post_type($post_data, $form){

if($form["id"] == '3'){
$post_data["post_type"] = "event";
}
elseif ($form["id"] == '4'){
$post_data["post_type"] = "schedule";
}
elseif ($form["id"] == '5'){
$post_data["post_type"] = "entity";
}
return $post_data;
}

to create my custom post type. Everything works fine except that the category does not update. Is there something additional I have to do to update a category on a custom post type?