grub fails when searching for a file when a partition is ill formated

[Arbiel (gmx)]

Hi

After I made a blunder in erasing the MBR and some additional sectors at 
the begining of my hdd, I rewrote my MBR with both testdisk and dd. 
However, I was unable to properly repair /dev/sda1 which remained in a 
faulty state.

I'm used to use "loopback", "linux", "initrd" and "boot" to boot from 
iso files when I want to install or reinstall a GNU/Linux distribution, 
and "search" to locate the device where my iso file sits. When I ran 
grub to boot in such a way, with my faulty /dev/sda1 partition, grub 
sent me a
"No such device" message, naming my iso file. After I zeroed the first 
MBR entry, grub successfully booted from my iso file, whithout me 
modifying anything else.

It turns out that this faulty partition also prevented a USB-generated 
USB key to boot the PC.

Arbiel