Comment 15 for bug 571678

The following page has a fix that seems to have worked for me.
http://www.ubuntugeek.com/quick-tipplymouth-themes-in-ubuntu-10-04-lucid-lynx.html

The part that worked:
sudo -s
echo FRAMEBUFFER=y >>/etc/initramfs-tools/conf.d/splash
update-initramfs -u

After reboot Plymouth appeared, although first time out of resolution, but on second boot it seemed to be right.