samba - Oct 2009 - How to turn off PDC lookup

I noticed that I can have my computer "ads join" a domain even when I
give a bad PDC.

It seems to catch the bad pdc and find the correct PDC. Is there a way
to turn this off?
Not that I don't like the feature, but I would like to say "use this
pdc I give you, if you can't, then fail".

Is this possible?

Thanks,
-- 
- Jeremiah Martell