Misbehaving mouse

Freaking mouse.  I have a wireless mouse which when was new I used to like a lot.  It's not just wireless (not Bluetooth though), but the receiver acts as a battery recharger, so it's really convenient.

Well, it's been a good 2 1/2 years I've been using, and it's kind of getting tired.  One or two days ago I swapped batteries, and since then I've noticed that when I left-click, many times I might get double or triple clicks, which is really annoying.  A few months ago I also noticed that even if nobody's touching the mouse, the receiver will receive something, and the pointer will move slowly on the screen as if somebody were dragging the mouse.