Norton 2012 have a great Bug with quarantine restore
A Example:
Norton found a False Positive as "Trojan.Gen" and quarantine this File , now you go to Quarantine and Restore this False Positive File over the Default in the Window with the Exclusion check .
Norton now do not exclusion this File, Norton do exclusion the Signatur "Trojan.Gen" , that means in the Future you are not protected against "Trojan.gen" .
The error has been confirmed by other Users.