I am finding that my Archivist (5), Runecaster (10), Heirophant (1) cannot scribe many scrolls into his spellbook that the class description in the PRC manual says I should.
EX: Finger of death and monster summoning VIII
This limitation means that an Archivist needs to be kept single class so that the 2 spells per level auto learn allows spell scribing. But that is a bummer as no prestigue classes or can't get spells for high level spell slots.