Comment 3 for bug 79268

This sounds like the classic BIOS won't let grub boot an image stored past the 1023rd cylinder ( http://wiki.linuxquestions.org/wiki/GRUB#Error_18 ). The typical workaround for this is to create a /boot partition that is 100Mbytes or so at the very start of the partition. The installer (ubiquity?) should really use dmidecode to look at the BIOSes age (perhaps anything older than 2001) and refuse to install/set up a boot partition/warn the user clearly if it is too old...

Probably related to bug #34353 ...