samba - Aug 2007 - IDMAP and RID problems

I am trying to get the rid back end to work for samba so that the UID 
and GID are predictable.  Here is my smb.conf file.  Anyone see any 
problems with this?  When I use the default of tdb it maps UID just fine 
but this config is not working.

Thanks

Mark

[global]

   workgroup = XXXX
   server string = Samba Server
   security = ads
   encrypt passwords = yes
   realm = XXX.XXX.EDU
   winbind separator = +
        idmap backend = rid
        idmap uid = 10000-20000
        idmap gid = 10000-20000
   template shell = /bin/bash
   template homedir = /export/home/%U
   log level = 5
   socket options = TCP_NODELAY


-- 
Mark Campbell
Systems Analyst
Digital Library Technologies
The Pennsylvania State University
mcc171@psu.edu, 814-865-4774