Notes for myself. Boot from Ubuntu Live CD.
sudo su
mkdir /nix
mount /dev/sdb2 /nix
mkdir /nix/back
cp /nix/truecrypt.mbr /nix/back/truecrypt.mbr
cp /nix/truecrypt.backup /nix/back/truecrypt.backup
rm /nix/truecrypt.backup
rm /nix/truecrypt.mbr
sudo dd if=/dev/sda of=/nix/truecrypt.mbr count=1 bs=512
sudo dd if=/dev/sda of=/nix/truecrypt.backup count=8 bs=3225
sudo grub
root (hd1,1)
setup (hd0)
quit
gedit /nix/boot/grub/menu.lst
### END DEBIAN AUTOMAGIC KERNELS LIST
title TrueCrypt
rootnoverify (hd0,0)
makeactive
chainloader (hd1,1)/truecrypt.mbr
boot
http://ubuntuforums.org/showthread.php?t=761530