When encrypting a disk when a 3ware RAID controller is connected, you receive an error message and disk encryption fails. If the 3ware RAID controller is disconnected, you are able to encrypt successfully.
This applies to PGP Desktop 10.2.1 MP3
Unable to start encryption, unknown error: 11980
Symantec Corporation is committed to product quality and satisfied customers. This issue is currently being considered by Symantec Corporation to be addressed in a forthcoming version or Maintenance Pack of the product. Please be sure to refer back to this document periodically as any changes to the status of the issue will be reflected here.