Automattic/Edit-Flow — pull request #201 by tannerm (2013-07-16 00:27:20+00:00)
Title: Fix issue where auto setting a usergroup to follow a post creates a new usergroup based off of the usergroups id

...s and force usergroup IDs to be integers

$user_group->term_id returns an ID of the term as a string and when wp_set_object_terms is run it creates a new group with that ID name instead of finding the term. The fix is to force each of the $usergroup values to be an integer.