I had this happen to me for the first time this weekend also. It was also a hot day with the car parked outside, which is rare as the empeg is usually pulled out and my car spends the majority of the time out of the sun. Luckily it was only parked there for a few hours and my battery was fine.

I've written this off as the price of being able to turn the stereo back on after the car is off. However, it might be a good idea to try having the empeg not wake up by IR, only physical buttons, and perhaps not the knob as it's known to be noisy.

Matthew