In my experience as an Apple Certified Tech. this is usually due to SMC firmware needing to be upgraded. You can go to the following link and download the update: http://support.apple.com/kb/DL350
In my experience as an Apple Certified Tech. this is usually due to SMC firmware needing to be upgraded. You can go to the following link and download the update: http://support.apple.com/kb/DL350
In my experience as an Apple Certified Tech. this is usually due to SMC firmware needing to be upgraded. You can go to the following link and download the update: http://support.apple.com/kb/DL350