Xperia Arc S Issues I need help on

[Guest guamzintrusion19]

Hi, everyone! First and foremost thank you to Modaco for this place where newbies like me can all get help from!

I bought my first android phone last Friday -- Xperia Arc S, and now I'm having two issues I hope someone can help me with.

1) Battery drains very fast -- 12 hours at minimum usage (call, text, a few 5 or 10min games)

2) The phone is heating up -- left side, the part below the camera and flash. this happens everytime i play games within 5-10mins or play videos.

Here are the steps I've taken to hopefully resolve the problem:

- took it to the service center and they reprogrammed the phone. they can't explain unfortunately why they had to reprogram and what caused the heating. They asked me to monitor the phone and bring it back in case it happens again... and now it's happening again...

- I searched online and discovered that the heating of the phone might be caused by a lot of applications running in the background. I downloaded a task manager but everytime i use it the applications would run again in the background after a few minutes. Is there any particular task manager/task killer that's more effective? Or anyway at all to get rid of these running apps in the background?

Please let me know if there's anything else I can do to prevent this from happening. Thank you all in advance!