My wife's Black 2.16 gHz (OS 10.5.2) started doing something a little odd. When the battery is nearly out, she'll shut the lid and plug in the adapter. When she reopens the lid, the screen comes on in black and white and stays that way for about three seconds before it reverts. It is only one year old and she is a light user. Is this something I should get checked out for her? We've got AppleCare on it.