Having problems with starting vehicle when it sits for any long period of time espically when cold. Going into work and coming back 9 hours later and the car won't start and will need to be boosted. I will be on the third battery as that's what the dealership thought it was. I think something might be drawing from the battery. It seems like a fairly common issue, but I have no idea where to start. The dealership is useless even though the car still has a CPO warrenty. The car has advanced key, MMI and NAV. I have read that it could be the advanced key but am not sure. Any thoughts?

http://uberlame.com/a6_tsb/Ignition%...02019143-5.pdf
http://uberlame.com/a6_tsb/Electrica...Dead%20(2).pdf