Software Updater wants me to do a partial upgrade, and the list of changes shows that it removes the grub-efi-signed package and replaces it with the regular unsigned grub-efi. I tested this in a VM, and it broke Secure Boot support.
Clean installations are also broken with the latest 14.04 LTS ISO. It fails during installation of the signed GRUB EFI package and crashes ubiquity. Only workaround is to install without an Internet connection.
So far I've just installed updates with the Continue option without doing the partial upgrade, but it pops up every time the updater runs. Is this going to get fixed? Why is it happening? Are they shuffling around some packages on the repositories?