The password and username used to log into any servers either gold or silver is same, it can be that u might have changed it to a new password and u might have forgot it and the password has been saved to your you pc if u are sure that isn't the case try logging into gold server with same password and then logout and try silver if u were able to log into gold and not silver it might be some bug which will be dealt by the staff please confirm that u were able to log into gold with the password but not silver this might help the staff . Thank You.