I apologize if I seem to be insulting you here. Maybe the answer is simple for you. Are you talking about sleeping or hibernating? Up until recently mine was draining after I had closed it. I had assumed that closing it caused hibernation, I was wrong. The default setting was set to sleep. I mapped the fn-moon key to 'hibernate' and now use that when I'm shutting it down if I don't want to do a re-boot (which takes freaking forever on this thing).
That solved my problem, I assumed closing the lid made it hibernate like other laptops I've used. That's not it's default setting an you can change that. Now I hibernate quite often since it takes very little time to come back alive and is well worth saving the battery.
I imagine that once I upgrade to an ssd hard drive, hibernation will be very quick.
