I have the same problem. The mouse does not respond to movement, but oddly enough the left and right click and side buttons work. Tried everything I can think of (reinstall drivers, the software, use the tools on the Theron mouse page), but nothing helps. I also noticed that the dragon symbol on the mouse is very faintly illuminated. I am guessing this is the firmware update problem. I am disappointed by the software using with this mouse. I got the mouse about 2 months ago. If I could get the older firmware to try I would greatly appreciate it. Thank you.