I get that sometimes too- superreading and getting nothing. That's when I switch to skittering/rapid reading. Guess you could call it skittering/dipping, who knows. Sometimes I superread the whole book without dipping into anything (even when I want to) just as a brief review before I skitter/rapid read. SuperReading isn't for comprehension, it's for turning the pages into a huge field you're looking at all at once just waiting for things to jump out at you. If nothing does, don't worry about it. After you do it just go on to skittering.
