If you feel like you're skimming, it could be one or a combination of a couple problems:
1) Problems with the PR step itself (sometimes if I'm in the wrong state will I PR it just won't work until I PR it again under better circumstances).
2) You need to slow your rapid reading down (if I'm in the middle of a bad novel, this is a big problem)
3) Try using skittering (I've decided against it, but maybe it'll work for you).
I'm not sure if I should tell you this, but if you promise not to rely on it heavily, then I'll tell you. Sometimes I use the Evelyn Woods Speedreading technique to activate (described as Andy as the Super Duper Ultra Fast Megazord Lightning Speed Hand of Death, or something to that extent). In this technique you place your middle finger under the word you are reading, then move it quickly, forcing yourself to read the word above it. I use this when I realize I'm going too slow or when I'm drifting to get my consciousness back, but to be honest, if you get dependent on it, you'll limit yourself, since your eyes can actually move faster than your hand.
-Ramon
