I installed a fresh 12.04 and tried to mimic what I had for 10.04. swap should be encrypted with a urandom key and there's another partition that will contain home and other directories.

# cat /etc/crypttab | grep -v '^#' | grep -v '^$'
cryptswap /dev/sda5 /dev/urandom swap
encriptado /dev/sda6

# grep -e 'cryptswap' -e 'encriptado' /etc/fstab
/dev/mapper/cryptswap swap swap defaults 0 0
/dev/mapper/encriptado /encriptado ext4 defaults 0 0

I also apt-get install cryptsetup

When I boot, the system says (try to translate) that either the partition is not found or is not ready. I should wait, press M for manual or S to jump over.

What am I missing here?