Comment 8 for bug 1066294

@alpha1: I'm just another vaguely-confused "end user" like you; as far as I can tell there should be "no reason" for the kernel to *demand* PAE aside from Ubuntu apparently wanting to make sure all their users have W^X protections (given Ubuntu's popularity among distributions, that's a fair point, but only the subset of users with PAE-less hardware would be vulnerable if they simply gave up on the apparently annoying-to-maintain emulation patch) ... and guarantee that people with >4GB running 32-bit can see all their RAM (the main reason PAE exists).

As far as I can tell the 'official' solution is to hang back with 12.04 LTS and see what happens when the 'LTS' runs out. I don't think many other distributions have made the same decision yet (some people have pointed back to 'plain old Debian', for instance) and there's always the "fun" options of customizing your own kernel or trusting someone's unofficial build - so if you want to stick with 12.10, check around the forums for links to PPAs.