[CentOS] centos authentication via ldap produces no name shell prompt

Hello,
    I'm trying to set up centos 5.1 to authenticate against an openldap 
server. I've got the authentication working, in that i can log in as a user 
contained within the ldap database but not in the system passwd/group files. 
The problem is instead of a prompt that for example looks like this:

(username)@hostname:~/$

i'm getting this:

(I have no name)@hostname:~/$

    Aside from this everything works, i can finger, use id, etc. It's 
annoying and i'm thinking it might be a symptom of a misconfiguration. Any 
suggestions?
Thanks.
Dave.