This seems to have been a corrupt /etc/default/grub; not clear what happened to it.
Dave ** Changed in: grub2 (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/721563 Title: package linux-image-2.6.31-11-rt 2.6.31-11.154 failed to install/upgrade: subprocess installed post-installation script returned error exit status 127 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs