Mac OS X May Exhibit Problems With IPv6

More information is available on Slashdot. In short, one reader observes:
if you’ve got a server that according to DNS is available both via IPv6 and IPv4, and the IPv6 address is not working, and the IPv4 address is working, the systems in question will fail to connect to it, even though they could if they’d just fall back to IPv4.

Something to consider as we are thinking about implementing IPv6.