samba - Apr 2006 - If I use "valid users" option, I can't log into the domain

Samba 3.0.22-1 on FC5

I can log into the domain, but if I set the "valid users" option to 
"@users", I can't log in anymore to my Samba domain.

My user is a member of Unix group "users"
Unix group "users" is mapped to Windows group "Domain Users"
I can still access \\<samba_server>

... but I can't log into the Samba domain.

Where am I going wrong?


Thanks,
Steve :)

This is what appears in the machine's log file when the password error 
happens:

[2006/04/05 04:22:05, 0] lib/debug.c:reopen_logs(597)
  Unable to open new log file /var/log/samba/valiant.log: Permission denied
[2006/04/05 04:22:06, 0] lib/util_sock.c:read_socket_with_timeout(492)
  read_socket_with_timeout: timeout read. read error = Input/output error.
[2006/04/05 04:22:06, 0] lib/util_sock.c:read_socket_with_timeout(492)
  read_socket_with_timeout: timeout read. read error = Input/output error.
[2006/04/05 04:22:06, 0] lib/debug.c:reopen_logs(597)
  Unable to open new log file /var/log/samba/valiant.log: Permission denied
[2006/04/05 04:22:07, 0] lib/util_sock.c:read_socket_with_timeout(492)
  read_socket_with_timeout: timeout read. read error = Input/output error.
[2006/04/05 04:22:07, 0] lib/util_sock.c:read_socket_with_timeout(492)
  read_socket_with_timeout: timeout read. read error = Input/output error.

Unable to open new log file? - /var/log/samba/valiant.log *is* the log 
file!!

Steve