[CentOS] help with samba and ldap on centos 5

Hi everyone; I'm having some trouble with samba on a centos 5 box; the 
box has been configured to authenticate against an ldap server via 
authconfig....authentication for normal use (console, ssh) works 
great....I'm having some trouble with samba using single ldap users or 
local users....It's rather weird, shares in which access restrictions 
are based upon ldap groups are working fine, getent group shows local 
and ldap groups, however attempting to assign access to a share for 
either a single ldap user or a local user doesn't work, and produces the 
following error when trying to hit the share:
smb_pam_passcheck: PAM: smb_pam_auth failed - Rejecting User myuser1 !

For local users, I've added local os accounts as well as accounts in the 
samba database with smbpasswd
Any ideas? Thanks for your help.

Aaron