The PDF-page 89 says explicitly you can bank skill points, or spend them on a new skill point. (In italics it says so again.) In this case, I assume you need a careful look at how you interpret the rules. If you follow the pyramid example on this page, you could say that if you throw up a skill to Good, you leave a Fair blank, which you could fill up with an Average slot, which means you need 2 Skill Points. If your GM allows this: hurray for you! Technically this is impossible, because neither of these skills could be singly upgraded, as the pyramid will not hold them up, therefore, you need an extra skill in the base to hold it all up. If you read the example closely, it still requires you to buy that new skill with the banked skill points, you can't just get a 1-point rebate if you shift all at once. Because in the example they are talking about getting a new Average skill to Good, not an existing skill to Good with that pyramid.
So, yeah, they say banking Skill Points, but the results are the same: you must uphold the pyramid.
My two cents about banking at char-gen would entail that you spend all your points, unless you have a very good character reason for doing so. Just being an amnesiac is not enough, because you either still need to flesh out his history, or be at the mercy of the GM as to what Skills your character happens to have. Think about it: if he was a soldier, but was hit in the head with a bullet, barely survived several years of coma and awoke without much of a memory, his body would very likely still have all the combat reflexes he learned (Athletics, Fists, Guns, etc.).