Fatal error after installation Civic Subscribing

5.x-1.2, Code, support request, normal, active

After installation, I get this when clicking on the Admin - Configuration - Subscribe link,
Fatal error: Call to undefined function crm_get_groups() in
/public_html/demo5/modules/civicrm_subscribe/civicrm_subscribe.module on line 43
Did I d something wrong?
I have Drupal 5.7 and Civic CRM 2.0 installed properly.
Thanks for the help.