Ok - Here we go - Let's get you up and going. I need you to fill in the blanks.

Is DNS ok - for the Domain and the NAS Server - ping by name on both?

Was there a change in the Domain Server - add or check to see if there is a reverse address record for the NAS Server

Try changing to PDC then back to ADS or unless this a PDC

Re-set the Domain password on the Windows server - go to the users names and find the admin name right click then change password - then enter the password again into the NAS Server.

Please check all time zones and time setting.