Please do me a favor, inspect these files:
/etc/nsswitch.conf <= this file should contain entries with "centrifydc" on passwd, shadow and group
/etc/pam.d/system-auth <= this file should have a set of lines inserted by Centrify
/etc/krb5.conf < = this file should be populated with information about your domain controllers
Also, please run adcheck [domain.name] and let's go from there.