4. Error -40 on clients running Mac OS X 10.2.x. Retrospect generates an error: “Can’t read file retropds.22, error -40 (file positioning error)” resulting in the “retro22.pds” file not being backed up. This file is necessary for the Retrospect client software to operate correctly. Dantz is working with Apple to solve this problem. In the meantime, the Retrospect client software should be reinstalled manually following a Mac OS X 10.2.x system restore.