[Opserty]

Two things:

1. You shouldn't be editing files, it means you have to edit files every time you upgrade
2. You are running an extra query on every threadbit (thats 25 queries extra on top of the ~14 or so there)

Here is the plugin we use:
Hook Location: forumdisplay_query
PHP Code:

PHP Code:

$hook_query_fields = ", user.usergroupid";

$hook_query_joins = "LEFT JOIN ". TABLE_PREFIX ."user AS user ON(user.userid=postuserid)"; 


The you can use:

PHP Code:

$thread['usergroupid']