Kerveros and windows interoperability

[ADMG]

I've a Kerberos network with Unix and Windows Clients. For the windows one,
I did all the steps which are described in this page from Microsoft :
http://www.microsoft.com/windows2000/techinfo/planning/security/kerbsteps.as
p

After regarding the logs on the KDC, I can see that the client is
authenticated but Windows disallow the account to connect (it gets his TGT).
All the mapping users are good.

Anyone have some ideas ?
Thanks
Jahnoel