On my iMac (2008), the mouse that came with it is acting strange. It does not want to easily respond to clicks as I click on things. I have to click at least a couple of times before the thing I'm clicking on works. For instance, if I want post this message, clicking on "Submit New Thread" takes about three clicks before it actually works. It has to be a problem with my mouse because I plugged in the mouse from my eMac and it works perfect. Do I have to clean it? is there some technical thing I have to do?