Repeat sleep/wake cycles create runaway ram hogs

After a couple days of working during the day and shutting the lid at night for it to go to sleep (I'd rather keep it in sleep than shut down while working on a project), I notice 2 processes start to look more and more like ram hogs - like a snowball rolling downhill. except each time it sleeps/wakes, it rolls down another hill but then stops during the day. These two processes are launchd and pboard. I know they're important and can't stop them, but they probably shouldn't be getting to the point where each take up about 600mb ram each - not leaving much left of my 2gb total for normal work. I have to restart completely to get it back down to under 1mb each, where they should be. Is this a bug in Leopard? Or just another one of it's "hundreds of new features"?