My iPod Touch won't turn off

Ok, I know how to turn off my iPod, by pressing the sleep/wake button and sliding it off. The problem is, whenever I do that, the apple logo appears and it turns on 2 secs later. So it stays on all the time, and turns off only when the battery runs out. The screen goes black when i set it to "sleep" or whatever its called, but it still wastes battery, so I know its not off. Any suggestions? Thanks in advance.