Comment 27 for bug 26058

Hm, I compared only the first sector and those were the same. I'm a bit busy right now and could probabably get back to this in two weeks. Meanwhile, I "fixed" the problem by hand-installing GRUB on Ubuntu's partition (/dev/sda2 vs. /dev/sda) and restored Windows' NTLDR using a Windows CD (FIXMBR, FIXBOOT). Then I followed the guide on how to load linux from NTLDR (basically: read the first sector of the partition where grub is installed, save as a file to Windows' partition, add a line to boot.ini, done).