Motorola A780

My A780 does shotdown very often. Sometimes couple of times a day without any reason. I can't turn it on right away. Have to take out battery out, put battery in, then can turn it on. The battery has to be charged daily to keep up.

It is very frustrated.

The retail shop told me that they try the phone with other carriers' SIM card without any problem I experienced. My carrier is Cingular.

Heard about this before?

Thanks

Benson