KE970 Power-up problem

Hi. I got LG Shine, known as KE970.
I'm loving the phone, but while I'm testing it, I found a problem.

When I turn off the cell phone completely by holding down the END button and try to turn it back on by the same method, the phone won't start. In order to resolve this problem, I had to remove and replace the battery. This symptom doesn't happen all the time tho. It's really strange.

When I first got the phone, I turned on the cell phone and played around with it with charger connected. I know that I'm supposed to wait until it's fully charged with power off but I couldn't resist!

Does anyone know if this's battery's problem or the phone's problem? I'd like to get a replacement if it's likely to be phone's problem. Thx.

Sounds more like a phone issue rather than a battery issue. I'd take the phone back and have them replace the phone with a new one.