DNS problem – possible unwanted use of ipv6 by dns – how to stop?

I've got a problem with DNS. I have safari hanging a lot from what seems to be a delay because my dns is trying to use ipv6 protocol to get DNS resolution. In the server dns log shows entries such as 16-Jul-2010 18:08:54.645 host unreachable resolving 'ns3.google.com/AAAA/IN': 2001:500:3::42#53 16-Jul-2010 18:08:54.664 host unreachable resolving 'ns4.google.com/AAAA/IN': 2001:500:2f::f#53 16-Jul-2010 18:08:54.824 host unreachable resolving 'ns1.timeinc.net/AAAA/IN': 2001:500:2f::f#53 16-Jul-2010 18:08:54.904 host unreachable resolving 'ns3.timeinc.net/AAAA/IN': 2001:500:3::42#53 16-Jul-2010 18:08:54.904 host unreachable resolving 'ns3.timeinc.net/AAAA/IN': 2001:500:1::803f:235#53 16-Jul-2010 18:08:54.941 host unreachable resolving 'ns2.timeinc.net/AAAA/IN': 2001:500:3::42#53 16-Jul-2010 18:08:54.958 host unreachable resolving 'www.cnnexpansion.com/AAAA/IN': 2001:503:a83e::2:30#53 Which I think are requests going out as ipv6. My router doesn't support that, so I end up waiting until an ipv4 request goes out. Any advice on where to look to turn off the ipv6 protocol? I have already turned it off in system preferences. And how did ipv6 get turned on? Thanks, Steve