So recently my santa rosa macbook has been a little stupid. When I'm running on the battery, without the power chord, the macbook sometimes seemingly shuts off. It goes into sleep mode, and if I press Return, it will wake up again (when the light has started pulsating). So each time this happens, I notice that a cross sign appears over the battery icon in the top right corner. Is my battery failing, after a mere 4months? edit: I should add that this dissapears when plugging in the power chord bump... can anyone help?