Is it a mouse or a touchpad? Cause there's a big difference. The synaptics driver is intended mainly for touchpads.
If it is a pad, you can try getting the newest driver. If thats the one you have, try looking on download.com for an older version.
If it's a mouse, with a cord and all that, try plugging it into a different USB port. And if that doesnt fix it, then buy a new one, cause the buttons in yours might be messed up. You can buy the new one and try it, most major retailers will allow at least a 7 day return window.
I reccomend the generic blueish greyish Microsoft mouse, just cause windows has NO problem with it, plus its like some 15 bucks. Pretty cheap.
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Every time you think you've made it idiot proof, someone comes along and invents a better idiot.
?the end of our exploring, will be to arrive where we started, and know the place for the first time. - T.S. Eliot