samba - Dec 1999 - smbclient -L and Windows 2000

Hello,

when I do smbclient -L //computer -U user
where computer is a windows 2k station,
smbclient do not show the services.

But if I know which service I can acces on computer,
I can connect with smbclient //computer/service -U user.

Do you have the same problem (It's difficult to connect if you don't 
know which services are offered...) ?
Why this problem with the -L option AND windows 2000?


Thanks for your help