I am using CiviCRM 4.5.5 on Drupal 7.
When I go to the settings page for my Case configuration (Administer -> CiviCase ->Case Types) I can add activities to the list of activities and appears to save. No error message is being raised. However if you edit the Case type again you will that none of your changes are there.
I will note that this instance of CiviCRM and CiviCase have been upgraded since somewhere in Civi 3.x.
Thanks in advance for the help.