call Apple and tell them about the problem.
They should be able to walk you through some troubleshooting procedures
I own a 2009 13" MacBook Pro. Whenever I close the lid to my computer and open the lid later the computer remains sleeping. This happens more than often. There have been times when I open the lid everything works properly with the screen prompting me to enter the password. So I'm not sure what triggers the issue. Whenever the computer remains sleeping I've tried taping the mousepad and the keyboard, but never get a response. The only thing that seems to work is using the power button which either returns me to the screen prompting me to enter my password or restarting the computer entirely. What is causing my MacBook to remain sleeping sometimes?