Laptop: Asus M3Ae
Problem: Can't mount root partition because of various ACPI errors. Breezy kernel works.
Solution:
1) boot with old kernel
2) sudo echo "libata noacpi=1" >> /etc/mkinitramfs/modules
3) sudo mv /boot/initrd.img-2.6.15-25-686 /boot/initrd.img-2.6.15-25-686.backup
4) mkinitramfs -o /boot/initrd.img-2.6.15-25-686 2.6.15-25-686
Thanks: Matthew Garrett