Mds Backupd

This problem is driving me crazy and i can't find a solution. I have this macbook that at the beginning was working great, but now, since a couple o week doesn't sleep anymore when left idle. I have tried quitting tons of deamons, programs turning off sharing and so on. Nothing. I set the sleep timer at 1 minute to check it. Nothing. It won't sleep. The curios thing is that...

backupd, mdworker, and mds. I know mds is related to Spotlight. It's been around since Tiger. mdworker is new to me, though, and I don't know what it does. backupd has a pretty clear name, so I assume it's doing the actual work. However, it is not always loaded, so something else must trigger it. Maybe a cron job? ...