I just confirmed a hunch I had: After reading a book with the excellent power-saving ipdf viewer, the frequency is stuck at 99000. This makes everything a bit slower (but also adds to battery life). Would it be better if the ipdf viewer reset the frequency to max (or to the original value)? Or perhaps make it configurable?
Of course, we could have a separate script "reset cpu freq to max" but that is a bit cumbersome...