According to several reports on the seagate support forums Seagate's recent firmware update for Barracuda 7200.11 drives affected by a faulty firmware is actually doing more harm than good and in many cases is bricking previously working 500 GB hard drives.
The thread is packed with owners of ST3500320AS model 500GB Barracuda drives who have attempted to update their firmware according to the Seagate knowledge base article. The update which is supposed to prevent failures is actually causing drives to be bricked.
For now the update has been "temporarily taken offline as of Jan 19, 2008 8PM CST for validation." There has been no official word from Seagate regarding the new issues faced by their users, however the company said yesterday they would provide free data recovery services for affected users so we can assume they will extend that offer to anyone that is affected by this latest issue.