Apple has released news that a small percentage of hard drives in MacBooks bought between May 2006 and December 2007 may fail under certain conditions.
Apple has determined that a very small percentage of hard drives that were used in MacBook systems, sold between approximately May 2006 and December 2007, may fail under certain conditions.
If your MacBook was purchased in the date range listed above and shows a flashing question mark on the screen, please take it to Apple or an Apple Authorized Service Provider and they will examine the hard drive to confirm if it is eligible for a replacement, free of charge, under this program.
If your MacBook has a flashing question mark appear on screen when it's turned on, and is a 13-inch black or white MacBook model with processor speeds of 1.83GHz, 2GHz, or 2.16GHz, and hard drive capacities of 60GB, 80GB, 100GB, 120GB, or 160GB, it might be an affected model.
Read here for the full details.