|To clarify... are you saying that the charger will not charge the camera if mains powered?|
Does this charger actually connect to the camera via detatchable usb cable; one end, using a standard usb connector goes into the charger, which can/ will also of course go into a standard usb port on your computer?
Many usb charged devices require a charging current that may not be available from one more more usb ports on a given computer.
Is the "new" charger the correct one - correct voltage etc.?