I'm in malaysia as well. i see a different problem related to the screen. happened once ( i think it's software related). phone wakes up, i look at screen. within about 10 seconds screen turns off.

a reboot fixed it.

i don't think your problem is battery related.

btw, my phone slows and UI becomes jerky when i access the mail app while i am updating mails. is that what everyone gets? usually happens when i have a lot to sync.

i also managed to make the phone hang to the point when i double tap i only see backlight turning on. nothing on screen. but i know phone is still running because i was in a call using a BT headset and i could hear the other party speak. he couldn't hear me though. reboot fixed it.