One of our servers runs CIFS for weeks at a time without a problem. Then
it starts rejecting CIFS logons (Domain passthrough mode). Doing a

26: Create NMAS Session

26: RemoteCheckIfLocalUser checking user.ou=activedirectory.o=company.

26: ERROR: -632 RemoteCheckIfLocalUser failed.

26: NCPCheckIfLocalUser failed -632

26: Client Session Destroy Request

26: Destroy NMAS Session

26: Aborted Session Destroyed (with MAF)

Bouncing the server bring everything back to normal, until the next time.

Any ideas?