DUDE! I had the same problem too with my Lachesis, exactly the same, all buttons and lights works, no problem at all except POINTER. Mine also the old one (not the 5600 dpi). This is what i do, I've been using it a year, and no more warranty for RMA and I decided to send back to the shop for repair, I lose the receipt too but luckily the shop recorded my mouse serial number and they knew when I bought etc. (I believe most of the shop out there does the same thing). 2 months after IINM the shop called me and the retailer said they can't fixed it for certain reason (I forgot why) and they decided to exchanged for me with the new one, and I got the latest version (5600dpi) with no warranty for free.    If you still have the mouse, I would recommend you to send it back to the shop and let the retailer to decide, if you're lucky enough, they will exchange a new one for you. It is worth to give it a try though.

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