I just installed ubuntu 7.10 server on a Virtualbox machine and when I tried to boot it for the first time I got this error, "Panic: CPU too old for this kernel"
Apparently Virtualbox does not support guest PAE.
To fix it I had to boot up to the install cd and go into "rescue a broken system". After going through some hardware detection steps I finally got shell access. From there I ran "apt-get update" and "apt-get install linux-generic" to install the generic linux kernel. After rebooting I had to press the 'Esc' key to get the grub boot menu list. From there I was able choose to boot using the generic kernel. After booting up I modified the /boot/grub/menu.lst file so that it boots using the generic kernel by default.
