Such zones by this and other makers are not safe enough without backups. As a Windows PC (or even other systems) this is how most figure out we can't go without backup copies.
To recover would have you asking Maxtor or who owns it now. If it was mine I would have wiped the drive, forgot the Secure Zone and made it a normal volume that is easy to backup.
I set 50gb in the Secure Zone with password that somehow I cannot repeat thus it is locked. Is there any way of deleting/emptying its contents or the secure Zone as it stands and re establish it with another?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic