I've just now completed the quest for Kelner that allows me access to the Dispel Barrier Spellbook; happy me.
However, when I go to read the book, in spite of the fact that it tells me I've increased my skill with the Dispel Barrier spell, I do not learn the spell. If I try to re-read the book, it tells me I don't learn anything new.
I've reloaded the game and tried this over and over again several times, all with the same effect.
Is there anything that can be done? Or do I get to finish the game without this spell? Being a perfectionist, and thinking of all the goodies I'll miss out on without it, I'd rather not.