MBP Battery Drains 2% Per Hour When Unplugged

I've been going round and round with the Genius Bar and AppleCare Depot. Purchased MBP in January 2008, I noticed a few months ago that when I completely shut down my MBP and unplug the power, the battery will be completely drained in 2 days. I have no USB devices plugged in and I'm sure its completely powered off. If I remove the battery and set it aside for that long and then plug it back in the battery has lost virtually no charge. So something inside the laptop is discharging the battery at about 2.1% per hour (I have been studying the problem for weeks and that percentage is the same every time).

So far applecare has replaced my battery twice, the complete power circuitry once, and the logic board once. I have been without my laptop for a total of probably 4 weeks so far. I took it back to genius bar and they have studied it for a full week before sending back to the depot to replace more things. So far, every time its gone to the depot it has been returned in the same day (thus proving they haven't tested it unplugged for any long period of time. And every time it has returned with a dead battery and the same problem.

I'm rapidly losing confidence that anyone knows how to fix the problem. Does anyone have any advice for what I should do when the laptop inevitably returns with the same problem.