Linux, AD, and sharing folders?

[Scott Ehrlich]

I've got Ubuntu and CentOS 5 boxes joined to a Windows AD domain,
using native configuration files I figured out - no Likewise or any
other third-party helper tools (no offense to the third parties - just
my choice).  No local accounts.  Users are able to easily log into any
Linux box with their AD accounts.

I tried a simple configuration of smb.conf to share a mounted
directory for a drive physically connected to the Linux box, but if I
use a Windows box on the domain and select Start > Run > \\linuxbox
and then select the shared directory I created, I get prompted for a
username and password.    Both the Windows box and that Linux box with
the share are already part of the domain, so I shouldn't be prompted
for my credentials. But, I enter them, and I get yelled at immediately
to enter them again.

I have tried a variety of things for smb.conf from endless google
searches and /etc/init.d/smb restarts.

So, what are the magical files and commands on the Linux side to
permit anyone on the domain to smb mount a shared folder on a Linux
machine that is on the AD domain?

Thanks.

Scott