The M570 is on it's last legs with me. The unifying receiver thing just isn't working for me. I've replaced it once, and it's failing again. Very frustrating when, on fresh batteries, the trackball just stops working.
I've been doing some research, it looks like the M570 is the only wireless trackball out there with the ball for the thumb. I will either have to switch to a mouse, a different kind of trackball, or a WIRE. The wire will be a problem, I'm mobile a lot, and I'd prefer wireless.
Looking for ideas, and I apologize for recommending the M570 to everyone here in other posts. What a turkey this thing is!