Installing the upstream 3.1.4 package did not solve the bug for me, but for the record, here's the direct link to the bug:
http://www.virtualbox.org/ticket/6100
Booting the image with acpi=off (by pressing F6 and checking the option in the Ubuntu bootloader) as suggested there as a workaround did allow me to boot the image with virtualbox-ose 3.1.2-dfsg-1ubuntu1 (the Lucid one).
Installing the upstream 3.1.4 package did not solve the bug for me, but for the record, here's the direct link to the bug:
http:// www.virtualbox. org/ticket/ 6100
Booting the image with acpi=off (by pressing F6 and checking the option in the Ubuntu bootloader) as suggested there as a workaround did allow me to boot the image with virtualbox-ose 3.1.2-dfsg-1ubuntu1 (the Lucid one).