unable to boot chromiumos "vanilla" from hard drive

unable to boot chromiumos "vanilla" from hard drive

I'm at the end of my teather here.
I have a Thinkpad X220 (last year's model) which boots with EFI, and I'm
trying to install Chromium OS on it. Hexxeh's Vanilla usb image boots from
USB fine, and EVERYTHING works, even suspend.
I follow the instructions to install it to disk via the chrosh command
"install", everything goes ok. I reboot and am faced with the grub 1.97
sh.grub> prompt. all the text is orange rather than white, if it matters.
Typing ls yields just (hd0), no partitions (even though gparted says there
are all 12).
No messing around with grub works, because it doesn't recognise any
partitions, just the one disk, hd0.
The same USB image succsessfully installs chromiumos on an old non-efi
laptop I have lying around. I can only assume it is grub 1.97 not
supporting efi?
I would really like to know what's up, thanks in advance!