Originally Posted by
None of the above
I think I need to read up on GRUB as it seems to be more of an art than a science.
Actually, it's not at all difficult.
The structure is that there's a folder called "boot" on each logical drive (the home of the relevant distro). In that, there will be various files with config... and initrd... and other such. Those are the "boot-up" stuff.
Under that, there's a folder called "grub" which contains "menu.lst" which lists the boot alternatives and tells the machine how to load each.
Quite often, each new install sets up its own menu.lst with its boot settings and maybe no others. If you edit in the other distros, and their load instructions, the choices will reappear.
The only trick is knowing which logical drive has the boot instruction that you're actually using. Don't try to change the logical drive; just edit in the missing code.