Here's another data point. My wife's Canon 7D started draining the batteries. (Around the same time it also started reporting that it couldn't communicate with the battery, so this may be a different situation.) We lived with it for awhile since we didn't want to send it to Canon and just made sure we always had fresh batteries when going out for a shoot.
Eventually, we stopped by the local camera shop where it refused to behave like that, but he upgraded the camera's firmware anyhow. From that moment on it recognized all batteries and stopped draining them.
