While trying to troubleshoot some problems with my ipw2200 wireless card
I noticed that my machine is always broadcasting "ipv6 router
solicitation" requests. One machine I had before would always try to do
an ipv6 name resolution before doing an ipv4 resolution. I "fixed" it
by disabling ipv6 in my kernel. I attempted to do that in this present
case, but now I keep getting these messages in /var/log/messages:

Jul 17 10:14:00 aa kernel: ipv6: Unknown symbol secure_tcpv6_sequence_number
Jul 17 10:14:00 aa kernel: ipv6: Unknown symbol ipv6_skip_exthdr
Jul 17 10:14:00 aa kernel: ipv6: Unknown symbol ipv6_ext_hdr

Any idea where these are coming from, what problems this might indicate,
and how I can turn it off?