Macbook Pro doesn't automatically wake from sleep?

Hi earlier my MacBook Pro A1211 Late '06 was working fine and whenever you opened the lid when it was turned on almost immediately it gave me a login however just now I have to press a key on the keyboard for it to wake from sleep.

Is this a setting or what BTW I've already tried PRAM and SMC Reset.
Thanks

This is a symptom sometimes displayed by older MacBook and MacBook Pro machines. The small magnets that are used to detect the opening and closing of the lid wear out or even fall out. When that happens, opening and closing of the lid is no longer detected. Could be what's happening with your machine. Check the location of the magnets at iFixit: The free repair manual.