i do agree this is a regression from jessie, but it is also something that happens only on some machines, so it may be something related to how kernel, bios, and various hardware interacts with each other.
if you are already using a customized preseed file for the installation, we found that this will workaround the issue, giving us a bootable system: d-i preseed/late_command string update-dev; in-target update-grub ; <additional commands you may want to run late in the installation> Thanks, -- Sandro "morph" Tosi My website: http://sandrotosi.me/ Me at Debian: http://wiki.debian.org/SandroTosi G+: https://plus.google.com/u/0/+SandroTosi