My sensitivity on my 518 seems to change on it's own. I have to reboot to get it back. I don't use the bindings for the dpi increasement, and in the software drivers, I changed the dpi to 800. Anytime I go into the mouse control panel, even if I don't change anything, the sensitivity changes again. Once again I'm about to go back to Razer. I've been back and forth between these 2 companies, nobody seems to make a mouse that freaking works. Days like today I miss the simplicity of my old Intelli 3.0....