I have some problems with my new LG GW525 phone.

1) When I change the wall paper picture, the phone restart
2) When I open the browser & goto a page, as soon as the page loaded the phone restart.
3) When I try to login to facebook, the phone says "Unable to complete the operation" after few minutes I entered the username & Password.
4) Push email it always says "try again later. The connection to the service unexpectedly failed. Please try again later"

I can manually receive emails without problem.

I thought of reflashing the phone to see the problem will get solved. But how can I reflash this phone? Please help.