Re: Ubuntu efi disaster.
Thank you both for your input, I freely admit that I know far less about Uefi than either of you. I just had a feeling it would be a disaster and of course it has been.
I will eventually get around to filing some bug (to be ignored probably) but in the meantime my energies are mainly devoted to trying to save my investment in this new laptop from being completely wasted.
My next option (having gone back to a Ubuntu only install - Clonezilla is absolutely wonderful) is to try installing another distro to see if their invocation of Uefi is any better than Ubuntu's.
Little as I know about the subject, I doubt very much that any distro would be able to undo the damage already caused by Ubuntu, but I am desperate, so I have to try anything I can.
Acer Aspire 5920G, Intel T7300 core2duo, Nvidia 8600M graphics. Linux Mint13 (unity-revamped), Ubuntu 12.10 (unity), Manjaro (xfce4), Debian Testing (gnome-shell), Crunchbang (fluxbox)