Comment 4 for bug 487689

I have xubuntu 9.10 installed with wubi. After regular kernel update (2.6.31-15) grub fail booting default kernel with message "load kernel first". I still can boot system using record for 2.6.31-14 in grub. Grub boot sequence for 2.6.31-14 and 2.6.31.15 are identical (see attachment).

Wubi installs linux into hdd image file which is placed on standard windows filesystem (in my case, ntfs). So linux is booted with loop option (maybe this is the key). I reproduce all booting steps with grub command line and everything is ok until I run
linux /boot/vmlinuz-2.6.31-15-generic root=/dev/sda5 loop=/ubuntu/disks/root.disk ro
which shows me "error: invalid magic number" and fails boot.