Reset to Factory setting

[moj...@gmail.com]

i tried to reset my G1 to the factory setting and it turned off and
when i enter my username and password it kept on saying

There is a problem communicating with the google servwers.

This could be a temporary problem or your sim card may not be
provisioned for data services. If it continues, call customer care.

[Vincenzo Iaciofano]

Same happened to me, the phone data is wiped with alt+L