Pre-authentication failed User Name: User ID: Service Name: krbtgt/PERMA-FIX.COM Pre-Authentication Type: 0x0 Failure Code: 0x19 Client Address:

Pre-authentication failed: User Name: ohqnas$ User ID: %{S-1-5-21-1957994488-115176313-1801674531-10659} Service Name: krbtgt/PERMA-FIX.COM Pre-Authentication Type: 0x0 Failure Code: 0x19 Client Address: 192.168.3.8 

I am constantly getting these events on my 2003 Domain Controller. The device its' alerting on is my NAS.