I also have the same problem, android os is just draining my battery. The problems began a week ago or something and happen very sporadic. Sometimes no drain, sometimes huge drain, I read that WIFI could be the isseu and at my girlfriends home at WIFI the drain is somewhat worse.
But turning off the WIFI doesnt always solves the problem. Restarting, cleaning cache and dalvik chache does sometimes works and sometimes does nothing.
But this morning I woke up and the drain was just really bad. My phone held up all day long pretty good. The phone was off the charger for 12-13 hour with 1 hour of screen on time and battery was down to 68% when I went to bed, nothing special but ok. When I woke up at 9 my battery was down 32%^.
The problem was that the android os never had slept when I was sleeping (9 hour battery draining).
Hopefulle somebody can help me. I believe that the service android.sonyercisson.wakeup woke up my android os all the time, even with the fact that I froze the service
. WIFI wasnt on when I was sleeping.