Authentication Problem with EAP-PEAP

[debug afone]

Hi,

I've got a new problem when I try to authenticate a Windows Vista client
with Freeradius.
Vista sends to the radius a User-Name like DOMAIN\USER.
When I use nt_domain_hack or the realm ntdomain, the domain disappear from
the User-Name attribute.

The authentication goes on, the login/password match in LDAP database but
EAP fails. Here's a trace : 

rlm_ldap: user nsouleman authorized to use remote access
rlm_ldap: ldap_release_conn: Release Id: 0
  modcall[authorize]: module "ldap" returns ok for request 3
modcall: leaving group authorize (returns updated) for request 3
  rad_check_password:  Found Auth-Type EAP
auth: type "EAP"
  Processing the authenticate section of radiusd.conf
modcall: entering group authenticate for request 3
rlm_eap: Identity does not match User-Name, setting from EAP Identity.
  rlm_eap: Failed in handler
  modcall[authenticate]: module "eap" returns invalid for request 3
modcall: leaving group authenticate (returns invalid) for request 3
auth: Failed to validate the user.

As you can see, ldap module returns OK but I have this message just after :
rlm_eap: Identity does not match User-Name, setting from EAP Identity.

Does anybody help me ?

Thanks.

Nicolas SOULEMAN.