Comment 143 for bug 477169

It isn't a problem of corruption...

These files are "compiled" when the system installs a new kernel or you enter an update-grub command. It seems (?) that initrd* is not "properly compiled" but grub.cfg is... anyway when the system restarts, grub doesn't find the content of these files [you can see this by enter cat /boot/grub/grub.cfg at the grub prompt, and you could try the cat command with other files, some will display ok, but many they will display the content of other files!!! Maybe grub doesn't load some necessary module, I don't know, but this only happens with files inside root.disk.] That why the "solutions" for this problem all involve to put /boot outside root.disk or at least grub.cfg.