After updating my ipod touch to the lastest software, screen not responding.

After updating my ipod touch (3rd Gen) to the lastest software (5.1.1), it's screen is not responding to the touch. After restoring it and loading it up with little music, it worked fine initially but only for a little while. I kept the ipod aside and the following day when I started to use it again, i faced the same problem. Again on restoring to to factory setting, the touch screen worked but for a little while.

The moment I keep it unused for a while, this problem comes. Also I can't even turn off the ipod, after keeping the center button and the slide lock pressed, the option to shutdown comes but as my luck has it, the touch screen doesn't respond here as well. I took it to the apple service centre and the folks there told me that I can only get it replaced but at the price half of the New Ipod !

This ipod was in perfect working condition until I did the software update ( now I'm thinking that why did I do it in the first place!)

If anyone has gone through the same trouble and found a way to resort this issue, kindly let me know as well. Thanks