The 2.6 series kernel only allows one owner of a block device (http://evms.sourceforge.net/install/kernel.html). I need to use the BD Claim patch.
This is the only change made to the default debian kernel. First get the config file of the debian binary (since we want it as identical as possible)
aptitude download linux-image-2.6.15-1-686
mkdir boot
dpkg-deb -x linux-image...deb boot/config-2.6.15-1-686
The config is now in the boot/config-2.6.15-1-686/boot dir
Now install the source (not sure of the dependencies)
Debian linux running a 2.6 kernel
To disable IPv6 you need both the following lines in your /etc/modprobe.conf file
alias ipv6 off
alias net-pf-10 off
Thanks to the guys on the #debian freenode channel for help with this.
Update
Moved the config to /etc/modprobe.d/local
Update
This stopped working on 2.6.18 on debian etch. Now my /etc/modprobe.d/local now contains just
blacklist ipv6
Apparently - in some cases this may still not work - in that case it is possible to try