It doesn't help that GRUB (whether 1 or 2) didn't support IBM PC compatibility unless you handled it manually yourself (something Linux installers also are guil

It doesn't help that GRUB (whether 1 or 2) didn't support IBM PC compatibility unless you handled it manually yourself (something Linux installers also are guilty of). This happened to mostly work units you dual booted into something that ran another program that ignored the no-man's land of cylinder 0, or had done something with CHS that grub didn't expect.