Comment 41 for bug 477104

Yes that seems to be the case, but I cannot reproduce this bug, and there isn't anything obvious in the code.
So it's a matter of narrowing it down a bit.
If you follow the instructions in #39 it might help. Hopefully this is reproducible on your side.
If it is an update-grub problem, it might be a matter of going through the /etc/grub.d scripts.