samba - Oct 2003 - The trust relationship between this workstation and the primary domain failed.

Samba DC (CVS 3.0.1pre1) on FreeBSD 5.1 and win2k (domain member).

On samba i have a some domain groups:
# net groupmap list
Domain Admins (S-1-5-21-826284196-2975262035-2440006394-512) -> wheel
Domain Guests (S-1-5-21-826284196-2975262035-2440006394-514) -> nobody
Domain Users (S-1-5-21-826284196-2975262035-2440006394-513) -> users

On win2k i cannot permit access to file for this groups:
C:\>cacls c:\file /E /G "Domain\Domain Admins":F
The trust relationship between this workstation and the primary domain
failed.
C:\>cacls c:\file /E /G "Domain\Domain Users":R
The trust relationship between this workstation and the primary domain
failed.

For users this works:
C:\>cacls c:\file /E /G "Domain\User":F
processed file: c:\file

samba 2.2.8a don't have this problem:

C:\>cacls c:\file /E /G "Domain\Domain Admins":F
processed file: c:\file

C:\>cacls c:\file /E /G "Domain\Domain Users":R
processed file: c:\file

C:\>cacls c:\file /E /G "Domain\user":R
processed file: c:\file

C:\>cacls c:\file
c:\file Domain\Domain Admins:F
        Domain\Domain Users:R
        Domain\user:R

Why ?

Thanks!