I had a similar problem as to what Greg mentioned above about LDAP hanging and not being able to login as a new user. However, after compiling libnss-ldap 251-5 from debian source, I have not encountered the problem again.
Mal -- cron hangs with LDAP authentication https://launchpad.net/bugs/24450 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs