hi guys i m a new galaxy w owner (1st ever smart phone) and need help with battery life.
with minimal usage, sometimes my single charge can last 36hrs, sometime cannot last even 24hrs. yesterday after install whatsapp, now my phone cannot even last 12hrs

normally unless i am actually using my phone, otherwise 99% of times i set my phone as below:
- wifi, gps, bluetooth = off
- mobile network = gsm only
- auto rotate = off
- packet data = off
- my location = off
- autosync background data = off
- brightness = around 10% of slider

what else can be done to increase battery life?
how to stop those apps running in background?
from time to time i see facebook, whats app, social hub (heck i dont even use this before), etc... running in background. after force stop they will come back...

betterbatterystats show that in last 12hrs (since full charge) that my partial wakelock:
ActivityManager-launch count:400+
AlarmManager count:900+
WifiService count:500+
ActivityManager-sleep count:900+

is that means that in past 12hrs my phone sleep and wake for 900+ times? how to i find out what cause this ?

pardon for long nag, i need some help here