Quite often in the past I’ve experienced a strange problem with my Macbook Pro where it would wake itself up shortly after I put it to sleep. I discovered that it only did this when the Airport card in my laptop was turned on.
After learning that I wasn’t the only one experiencing this problem, I wrote a program to solve the problem: Wireless Sleeper.
Just launch the program and let Wireless Sleeper do the rest. It’s a tiny, efficient program that silently sits in the background. When it discovers that your computer is about to go to sleep it will turn off Airport and wait 5 seconds to make sure that it’s off (this is necessary for the fix to work). Once your computer wakes up after its night of uninterrupted rest, Wireless Sleeper will turn your Airport card back on for you. It will even add itself to your list of login items when you run it so that you don’t have to worry about that too!
10.6 UPDATE: If you are running Snow Leopard please download this version instead.