I've seen this on one of my machines as well, I've fixed it with what I've provided below.
I've 8 PATA disks (4 of which make up a RAID1 array used for booting), and 3 SATA disks. /boot's device was /dev/md0 (Dan appears to have a similar configuration). During some previous upgrade, /boot/grub/device.map was regenerated, and it was missing some of the devices that made up the boot RAID array. That device.map is missing devices seems to be the problem here. Felix, as you mention, my solution was to run: grub-mkdevicemap --no-floppy which regenerated the device.map file. This time, the regenerated file was correct, and update-grub ran successfully. You could also edit device.map manually to make sure all required devices are there. -- Samat Jain <http://samat.org/> | GPG: 0x1A1993D3 Partner, Chief Technology Officer | Rhombic Networks, LLC A witty saying proves nothing, but saying something pointless gets people's attention. -- Anonymous (409) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]