OK, the problem is in wats-template.php
With version 3.0 some things regarding taxonomies and object types have changend.
You can use the new 3.0 function "register_taxonomy_for_object_type" or, for compatibility reasons, set the taxonomy for the 'ticket' object type manually like this:
function wats_register_taxonomy()
{
global $wp_taxonomies;
$wp_taxonomies['category']->object_type[] = 'ticket';
$wp_taxonomies['post_tag']->object_type[] = 'ticket';
}
Works for me - partly - the tags box doesn't show.
For 3.0 you should register the 'ticket' object type with register_post_type().
By the way, in your current version I see that you have added the post_tags to the 'post' object type:
register_taxonomy( 'post_tag', 'post',
array('hierarchical' => false,
'update_count_callback' => 'wats_update_ticket_term_count',
'label' => __('Post Tags'),
'query_var' => false,
'rewrite' => false) ) ;
Shouldn't it be like this?
register_taxonomy( 'post_tag', 'ticket',
array('hierarchical' => false,
'update_count_callback' => 'wats_update_ticket_term_count',
'label' => __('Post Tags'),
'query_var' => false,
'rewrite' => false) ) ;