Hello... I recently purchased a Microsoft Wireless Desktop, featuring the Wireless Mouse 700. The keyboard works fine (using it right now), but the mouse's laser shuts off (all the way off, no light) literally every two seconds. No amount of mouse movement can turn the laser back on -- I have to click the left button to reactivate it. Functionally, this means that every two seconds I have to click in order to get my mouse cursor to move, which is quickly driving me insane. Batteries are brand new. Am I missing something here, or did I just buy a dud? Any help would be greatly appreciated. - Stephen