Ah, ok, it not only didn't run update-grub, it didn't run update- initramfs either. I don't know if that was the extent of it, but running those two seems to have made it work well enough.
-- Latest edgy kernel fails to boot (2.6.17-4-k7) https://launchpad.net/bugs/52701 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs