Sounds like what happens to me - except I know why.
I have a cat that likes to bite the mouse wire. The wires inside the outer cover are very thin. So when my cat damages them it's enough to "short" out the signals. This confuses the computer and it freezes. A restart and all is OK until I move the mouse wire the wrong way and it shorts again.
Very annoying, thankfully a new mouse isn't that expensive, and I swear my next one will be wireless.
Maybe you don't have a biting cat, but your wires could have become damaged another way. Check the equipment for signs of wear, make sure the connection is good, and if that fails try a different mouse, it's possible the damage lies beneath the outer covering (eg. from a sharp kink) and you won't see it.
And you could try taking apart the mouse to make sure it's clean inside. My old ball types used to get a real mess of dust and fur.