[olug] DNS lookups lagging?

[DYNATRON tech]

it seems that my DNS lookups have about an 8 second lag in several linux
distros.
most recently i'm using mandriva, but it seems to be an issue for me in
ubunto as well as a couple other distros.
my laptop (windows OS) doesn't seem to suffer the issue unless i use an
ubuntu live disc.
i am using windstream DSL at my home with a mix of DHCP and static
addressing.
i did a mandriva install for a friend with cox internet (DHCP), and it
suffers the same lag on his connection.
most notably, the lag happens on the web browsers (firefox, epiphany,
konquerer)
the lag occurs only when switching between domains (google.com --> yahoo.com),
or a different host on the same domain (www.google.com --> images.google.com).
it does not occur when the target domain doesn't change.
what makes me think that it may not be a DNS issue, is that returning to a
previous domain will produce the same lag, even though DNS should have been
resolved and cached already.

is anybody else having the same issues?
i did a google search, but only unrelated results or people in forums
arguing about how to fix it.
all i can gather is that it might have something to do with network
filtering of IPv6 packets.
if this is true, what's the easiest way to disable IPv6?
i'm willing to try it as long as it doesn't require downgrading to a 2.4
kernel as a forum poster suggested.

thanks for reading!