Yellow Dog Linux

When using Firefox 3.6.17 on YDL 6.2 I get this message when going to ipv6test.google.com:

If you don’t fix your connection, you may experience severe problems connecting to Google and other sites on World IPv6 Day, June 8.

Doesn't give me an error when using Opera 10.63, but says:

You don’t have IPv6, but you shouldn’t have problems on websites that add IPv6 support.

You should have no problems on World IPv6 Day, June 8.

EDIT: here's another test site
http://test-ipv6.com/