Found the solution:
Entering set in the grub console shows the prefix points to EFI/ubuntu
instead of EFI/kubuntu. Boot the system, copy the folder
/boot/efi/EFI/kubuntu/ to /boot/efi/EFI/ubuntu/ and everything works fine.
This is definitly an error in the default installation configuration -
Same for me: Kubuntu 13.10 (stable, amd64), hdd+ssd, boot partition (+system)
on ssd.
After a (complete!) fresh installation the notebook boots into the grub console
instead of booting the system.
To boot kubuntu I have to type
configfile (hd0,gpt1)/EFI/kubuntu/grub.cfg
Everything else
