Power On when Laptop Screen Opens

A further question to this is the power button stopped working on my laptop.  It's not jammed, still functions fine, and is lit up but it will not wake the computer up anymore.  The computer is currently on but I do not want to turn it off for this reason.  Opening the lid at least wakes it from sleep.  Is there possibly a reason why this would not be working, other than it possibly being broken (though the laptop just sits on my desk so it's not like it could have dropped or anything).  Like I said, when I first got the computer, it was automatically set to start up, from a complete shut down, when the lid opens.  Thanks again!