I can confirm this bug on my system. I'm using an IDE drive and an additional SATA. Normally, grub-config wouldn't hose my system, but on the Dec 13th upgrade, it did. My root line was changed from (0,4) to (1,4) and left me with an unbootable system for a while (since it was hard to diagnose because the error was #15, File not found).
-- grub uses wrong bootparameters with sda after install https://launchpad.net/bugs/21186 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
