try to plug the mouse on a separate computer and see if its the same. I've had bad experience with sony in terms of hardware and software. But the cause for ur problem is pretty open ended since it could be a lot of things. But like the_prophecy said try it on a separate computer and see what happens. Worst case is that the USB port on ur laptop is dying. Its happened to everyone. but on a second note i've also had mouse issues before and found that it was somewhat loose in the usb port. brought a USB hub and problem solved =P