So I've had my macbook (2.4 core2duo, 10.5.2) for a few weeks now, lately if it has been closed while on battery power and then woken up the power icon in the menu bar flashes. It jumps between the power plug icon (for when its plugged in) and the battery icon. It seems to be randomly timed and theres nothing near the magsafe port. Any ideas? It stops flashing if plugged in or restarted.