@Adrian: Thank you ! @all others: Has anyone an idea ? I`m using CentOS 5 with: squid-2.6.STABLE6-4.el5 squidguard-1.2.0-2.2.el5.rf samba-common-3.0.23c-2.el5.2.0.2 samba-client-3.0.23c-2.el5.2.0.2 krb5-libs-1.5-29 pam_krb5-2.2.11-1 krb5-workstation-1.5-29