I purchased a Western Digital WD3200BEKT from Amazon and installed it today into my mid 2009 13 inch Macbook Pro. I booted from the DVD to reinstall OS X from a Time Machine backup. Here is where the problem began. With the new hard drive installed, the backlight for the screen and the keyboard would not come on. I could see the outline of the install menu, but the screen was not bright enough to see anything else. The keyboard would not light up either. I uninstalled the new hard drive and reinstalled the stock hard drive and this problem went away. Has anyone heard of a compatibility issue with the WD3200BEKT? I called Apple and they could not help me. Any ideas would be appreciated before I send the drive back to Amazon.