Norton Ghost Report Target DIsk Full

I receive this report whenever I do a backup. How can I fix it or how can I get this request to Norton.

The description for Event ID '100' in Source 'Norton Ghost 9.0' cannot be found.  The local computer may not have the necessary registry information or message DLL files to display the message, or you may not have permission to access them.  The following information is part of the event:'Description: An error occurred during a scheduled backup of drive C:\. Error EA390719: Target disk full.

Details: 0xEA390719

Source: Norton Ghost 9.0'