I have found the following two resolv.conf options to be extremely useful when standing up AIX systems that are tethered to a Microsoft DNS solution:
options timeout:1
options attempts:1 _place_holder;
The timeout option sets the initial timeout for a query to a nameserver. By default this is 5 seconds in AIX 6.1.
The attempts option is reducing the number queries the resolver is sending to each nameserver in resolv.conf.  _place_holder;By default, the number of attempts is 2 in AIX 6.1.
I am sure that this is most likely a by-product of the DNS configuration I am integrating with and not the Windows server software.  _place_holder;In any event, by  _place_holder;incorporating these values into my resolv.conf I have reduced the pain associated with ssh logins and Oracle RAC failovers for those LPARs required to participate in DNS provided by the corporate domain controllers.