Yep, Just don't work on a masters thesis or something of the like until you've beaten on it in games/burn in programs/benchmarks whatever. The only risk is your machine will crash and corrupt some data, in rare cases you might have to reinstall windows or something along those lines but ussually you'll just have the system lockup on you and need to restart.
Well, look's like nobody believed me when I posted pc100@133. After reading in other forum, I tryed it myself, and seted the pc100 to pc133, and voila, 415/510 in Sandra memory benchmark! Rock stable!!!