Comment 43 for bug 580408

I got same behavior during a "Software Updater" session.
A window with "shim-signed" title lists "GRUB install devices", from there I pick /dev/sda1, then after clicking "Next" button comes next checkbox "Continue without installing GRUB?", and there if I keep as "no" it goes back to first screen. The only way to "finish" the process is by selecting the "Continue without installing GRUB?" checkbox in second screen.