iPhone 3g gets stuck on charging HELP

Hello everyone, I need your help! I just recently upgraded my iphone 3g, 2 months old, to 3.0 and im not being able to charge it more than 55%. The right upper corner icon of full charged appers and then it stars discharging. Ive tried hard reset, full restore from iTunes with backup and without backup and nothing helps. Im out of the US right now, so I do not have an Apple Store near. PLEASE HELP!!!!
iPhone 3g, 2g, ipod touch 2g, iMac iPhone OS 3.0