Why does an unloaded alsa module consume more power than a loaded, suspended one?

It seems to me there must be some problem with power management somewhere if completely unloading a module has my netbook using more power (at least 1 W) than if it's loaded and the card suspended by the driver. What's going on here? This is just an open question for now. Any hints are welcome. I am aware obviously that the driver module has power management functions which cause this. The question for me is: Why is that so much more efficient than normal power management?