samba - May 2008 - Problem with kerberos + winbind + samba + ADS

I use winbind Kerberos + + + Samba AD and I have the following problem:

The client from my network when connected to the resource until it shows
them spend about 10 files. After everything is going superbly. It is the
first connection. It also happens when they stop using documents network
for a while and then when they return to look for something in the
resources to take them back.

It may be the ticket kerberos?

It seems as though the meeting had a time of life. Never should cut the
service simply that the first connection takes to show the data.

My krb5.conf

[logging]
 default = FILE:/var/log/krb5libs.log
 kdc = FILE:/var/log/krb5kdc.log
 admin_server = FILE:/var/log/kadmind.log

[libdefaults]
 default_realm = xxx.ES 
 clockskew = 300
 dns_lookup_realm = false
 dns_lookup_kdc = false
 ticket_lifetime = 24h
 forwardable = yes

[realms]
 xxx.ES = {
  kdc = xxx.es 
  admin_server = xxx.es
  default_domain = xxx.es
 }
 xxx.es = {
  kdc = xxx.es
  admin_server = xxx.es
  default_domain = xxx
 xxx = {
  kdc = xxx.es
  admin_server = xxx.es
  default_domain = xxx
 }
[domain_realm]
 .xxx = xxx
 .xxx.es = xxx.ES

[kdc]
profile = /var/kerberos/krb5kdc/kdc.conf

[appdefaults]
 pam = {
   debug = false
   ticket_lifetime = 36000
   renew_lifetime = 36000
   forwardable = true
   krb4_convert = false
 }




Esteban Torres Rodr?guez
?REA DE SOPORTE T?CNICO - Administraci?n de Servidores
Subdirecci?n de Sistemas Inform?ticos
Empresa P?blica Desarrollo Agrario y Pesquero, 
email: etorres@dap.es