I've found it strange that intelligence increases never see a retroactive increase in skillpoints in EFUSS and the base skill system where this occurs for every other attribute. An increase in constitution gives you hitpoints for every level, an increase in wisdom improves your will save etc. Why shouldn't the same occur for intelligence? You might say that you weren't as intelligent in your previous levels so you missed the opportunity to learn, but I would say that constitution suffers a similar logical problem. You weren't as healthy as you were then so you miss the opportunity to fortify your body. Besides which, rationalising the abstraction of levels and their relation to skills is a futile exercise.