Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great, but...

This mouse is great except for one major flaw. I haven't heard of it anywhere else but it has happened on 3 different computers. After having the mouse/computer on for extended periods of time, when I turn it off and then back on later, the optical light will not turn back on. It takes from a few minutes to several hours, usually the latter. Ruined the mouse for me...