Machine 1: two different versions of either Mandriva or Ubuntu start the kernel & then wander off into never-never land.
Machine 2: Ubuntu boots, but starting the installer is a waste of time, as you get a blank window, hourglass cursor, & hyperstasis. Mandriva boots, but the startup menu goes static. Forcing it into a text-mode install works perfectly, but the resulting system yields a static boot menu. OK, boot into rescue mode, switch the GRUB graphics off, re-install GRUB, all werx ferpectly.
OK, so Machine 2 is working, but I have no idea why. (-:
Oh, & on a completely different topic, I need to build a dependable list of reasonable things for children to do in & about Perth — in order to make completely different things work.
No, this isn’t contra, fair or balanced (AFAICT) in any way, but doing it will be a step towards avoiding some painful, distressing, short-sighted & destructive choices being made elsewhere.
So... no matter how random that you feel your choices may be, drop them in the replies here, even if anonymously. They may well help.