[Samba] winbind nsswitch problem

[Ben Lentz]

Greetings list,
I'm using samba 3.0.23a on a Fedora Core 5 system in a member server 
role in an Active Directory domain (security ads). My problem is that, 
although wbinfo -u and -g work great and can pull user and group lists 
respectively from AD, getent passwd and getent group do not. I've 
configured passwd: files winbind and group: files winbind in 
nsswitch.conf, and have configured idmap uid = 10000-20000 and idmap gid 
= 10000-20000 in the smb.conf file. testparm is clean, as is net ads 
testjoin. smbd and nmbd are running.

Running winbindd -i -d 10 & and trying a getent passwd results in a tiny 
amount of output from winbindd:
accepted socket 16
process_request: request fn INTERFACE_VERSION
[    0]: request interface version
process_request: request fn WINBINDD_PRIV_PIPE_DIR
[    0]: request location of privileged pipe
accepted socket 17
process_request: request fn SETPWENT
[    0]: setpwent
process_request: request fn ENDPWENT
[    0]: endpwent

... but no actual passwd data comes through.

I got this working several years ago with samba 3.0.10 on Fedora Core 1. 
What on earth could I be doing wrong?

Thanks in advance for any hints...