This also happens to me after a dist-upgrade. The kernel package can't create a ramdisk image, so system panics on boot, because it can't read the disk partition.
Running depmod. Finding valid ramdisk creators. Failed to find suitable ramdisk generation tool for kernel version 2.6.17-10-386 on running kernel 2.6.15-27-386 in /usr/sbin/mkinitramfs -- Edgy Beta cannot boot https://launchpad.net/bugs/63402 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
