CiviGroup Roles Sync fails due to undeclared variable $gid

CiviGroup Roles Sync fails due to undeclared variable $gid in the file civicrm_group_roles.module. The error is

Setup
Drupal 7.8
CiviCRM 4.0.5
Apache

Repro Steps
1. Install working drupal and civicrm.
2. enable user sync between drupal and civicrm
3. add user in drupal, ensure a matching contact is created in civicrm
4. create a new role in drupal called "employee"
5. add user from (3) to employee role
6. create group in civicrm called "our employees". Do not add contact into this group.
7. In drupal modules, enable CiviGroup Roles Sync
8. go to configure civigroup roles sync in drupal
9. click add association rule
10. select civicrm_group=our employees and drupal_role=employee
11. click add association rule
12. in drupal, click People in admin menu bar.
13. click the user from (3)
14. click edit
15. de-select the checkbox for the employee role (remove them from it). Click the save button.
16. select the checkbox for the employee role (add them from it). Click the save button.

results:
(1)A red error at the top.
Notice: Undefined variable: gid in civicrm_group_roles_add_remove_groups() (line 584 of /home/electrog/drupal/sites/all/modules/civicrm/drupal/modules/civicrm_group_roles/civicrm_group_roles.module).

expected:
No error.