30" Cinema HD display power switch

I just bought a 30" Cinema HD to replace my 17" Studio Display. On the Studio Display I could touch the power button on the display's front bezel to Power ON the computer and also to put it (and the display) to sleep. On the Cinema HD Display I can touch the power button to put the computer to sleep, restart, or shutdown. But I can't use it to power ON the computer. Is that the way it is supposed to work? Is pressing the power button on the front of the computer the only way to turn on the computer?