Instead of actually using them where they are found I decided to drag them along just incase I couldn't translate texts later on.
So you knew what was in them when picking them up without reading them? Reading them when found would've given you the translation skills... Not a real answer to the problem, but I find it pretty strange you're dragging books into your inventory without reading them <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
Now for the answer: some story-related objects will indeed "lose their powers" when taken into another act. Most of these objects, however, have "powers" you wouldn't need in another act (e.g. what are you gonna do with a coal barrel from act 1).. Except, yep, for Raanaar books that you've never read...