samba - Oct 2005 - idmap problem / Where is the shared module documentation?

I've spent a couple of hours trying to figure out why the Samba
3.0.20aidmap facility doesn't appear to be working when it works just
fine with my
current config file and 3.0.14a.

I'm getting "Username DOMAIN\MACHINE$ is invalid on this system"
errors in
the logs - which I believe I used to get with 3.0.14a until I enabled idmap.

Is this something to do with the --with-shared-modules config option? I
can't find documentation anywhere on what this option does, other than
someone mentioning that idmap_rid needs to be explicitly specified here.
Where are the docs?

Can anyone tell me why I'm getting the above error?

Please CC me as I'm not subscribed to the list.

Thanks,

Joshua Weage