For me this android OS battery drain starts as soon as I open asphalt 5, been like this on both jvk and jvb. Dont even need to play just open it and exit and android os starts draining. A simple phone reboot stops the drain though.
I get the same. Not just Asphalt .. any CPU intensive activity. eg. graphic heavy games like Dungeon Hunter 2, Asphalt5/6, GT Racing, Hero of Sparta, Hawx ..
I also get a drain immediately after removing it from charge.
If I reboot immediately after removing the phone from charge (and don't play any games) I get great battery life (approx 75% better than 2.2.1)
Since only a few people are complaining about this drain perhaps I need to flash my phone again ..