I have the same monitor, which works for me with 100Hz without any problems. You can't damage the monitor with it, because the panel simply refreshes faster. And the panel is actually designed for this. It could be that you got a monitor that doesn't work at 100Hz, but only at 95Hz, and that stays black or flickers at 100Hz. However, I have never had such an experience; the overclocking advertised by the manufacturers has always worked very reliably for me.