In Samba 3.0, the setting 'domain master = yes' is ignored unless accompanied by
'domain logon = yes'.  The justification for this change is that a machine which
registers #1b but does not register #1c will be confusing to Windows clients
that are looking for a PDC.  However, on a network that already has a PDC, a
Samba server can still cause trouble if 'domain logons' is set; and on a network
where Samba is only needed for DMB functionality (not logon functionality), it
does no harm to have 'domain master' turned on without 'domain logons'.  Now, it
also does no harm to turn 'domain logons' on whenever 'domain master' is set,
but this isn't what 3.0 is currently giving users.

Possible resolutions:

* change config handling so that either of 'domain master = yes' or 'domain
logons = yes' will promote the other to 'yes' by default.

* update the documentation so that 'domain master = yes' is deprecated,
presenting it only in the 'no' form for creating a BDC; restore 2.2-compatible
handling for legacy installs.

* update the documentation as above, and attempt to handle upgrading existing
config files at install time (ok, maybe this only works for Debian :).

* update the documentation, and have testparm throw an error when 'domain master
= yes' is set.

I'm happy to work up a patch for any of these, it's just a question of knowing
which way the Samba Team wants to go with it.