[Samba] BDC problem

[Vegeta]

I have te following bug:

I set up a PDC and a BDC using Samba 3.0.2a using LDAP as a backend (PDC has
the master LDAP as backend and BDC has the slave LDAP as backend).
At first things work fine.
If I shut down the Master, windows machines are still able to log in
authenticating against the BDC.
If I create a share on a windows machine in the domain I can access it from
linux when the PDC is down.
If I have a Samba member server, its shares are only accessible if the PDC
is up. It refuses to authenticate against the BDC when it is down.
It seems like a Samba bug, since the BDC works well for a windows member
server.

Is this bug known? Has this configuration worked for others?

Thanks in advance,

VS