Comment 16 for bug 653134

I'm pretty sure the Grub -> NT Loader -> Grub setup is a red herring though... My failing system is not a dual boot setup, so it's just NT Loader -> Grub. Unfortunately, I am not able to catch it and in /ubuntu/disks/boot/grub there is nothing (no grub.cfg) but to be honest, I don't know enough about how wubi works and where it points NTLoader to find and launch grub to really diagnose beyond this at this point.

I can imagine that updating grub during the Lucid -> Maverick upgrade could be the cause of this. If I get time, I'll see if I can rescue and get into the disk image for my wubi install and see what I can learn.