In device manager, usb hub - properties, power management, uncheck the box

most likely your wire is broken

Sounds like a cable connection issue.

You might have damaged the mouse lazer or the PC usb port as either hardware is not designed for that frequency and the symptom you have is what happens when it goes tits up.

Turn it down to 250hz, should still give a good boost over 125 and be better, or just get the closest mouse to the WMO with native 500 to see if that help.

In my experience this means the cable is starting to screw up, as h8m3 and FlashSoul said. I've had a WMO die in the past from this, and my current one is starting to do the same thing. If you can find the spot along the cable that is causing it, you may be able to buy yourself some more time by twisting it slightly and taping it.

In my experience it can be either the cable (buy 10 wmos in advance) or windows 7 or 8 usb power thing, which has to be disabled manually in all usb thingies.

I think Jamerio is right (I'm shit @ computerstuff tho)
But when I had the same problem I couldn't get it back to work so I reinstalled windows and bought new mouse :/