Ubuntu Lucid Lynx 10.04: Disable IPv6 (dmesg = no IPv6 routers present)

Problem: on default ubuntu lucid lynx setup ipv6 is enabled,
dmesg shows boot.log= wlan0: no IPv6 routers present
to speed up on a ipv4 network you should disable it.

– run #sudo nano /etc/sysctl.conf

add lines:
#disable ipv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

-quit save and reboot..
-to test system open terminal and enter #dmesg
-the message = wlan0: no IPv6 routers present
should not be seen!