Hi. First post. My less-than-a-year-old Macbook is acting weird. About a week and a half ago I decided to set up a logon password. Since then, the laptop will shut down instead of going to sleep. I've gotten rid of the password, but never know whether the mac will wake up when I open the lid, or shut down and have to be restarted. I've tried to be careful to not let the battery run down to zero, and avoid leaving it on the charger too long. I recently got a coolmat with fans and a usb hub and it seems to be running cool. Is this the beginning of a serious problem? Thanks in advance for any wisdom.