? = Waaahhhhh! My n900 has stopped working! "Safe" overclocking has to proven over time. It may work fine over the next few weeks/months, it won't explode or combust, but little things may start happening (e.g. random lock-ups, "unexplained" application crashes) you may not notice it straight away - no matter how many times you re-flash the n900 the problems will persist. Your device is now royally f***ed! I will wait a few months and see what happens before I try anything like this.