I checked the BIOS Battery and found that it was flat. The Bios did not emit the promised beep on low battery:-)
But in any case, this is clearly not a bug in the kernel/grub, so apologies for the noise. The delay in reporting was because the machine was dismantled, and replacing the battery turned out to be less than straightforward because of silly welds. I will try to close the bug if I remember how. ael
