I have Macbook pro 13" 2009 and running OSX 10.8.2. M4 firmware is 010G I just bought a new M4 512GB yesterday. I format the drive with Disk utility, install mountain lion, migrating from time machine. And everything seems to work fine. Then I closed the lid and MBP went to sleep. When I opened the MBP, it shows beachball and freezed. When I reboot, it just stays at grey screen as it can't find the drive. Even when I put the M4 in usb external enclosure and it doesnt read. This is within 1 day of owning this drive. Then I read from here: http://forum.crucial.com/t5/Solid-S...quot-disappear-quot-from-my-system/ta-p/65215 So I let it stay powered inside usb drive enclosure for 20min, and it's back to normal again. Does anyone have the same problems with M4? I can't believe I have to revive the drive like this. And from reading Crucial's website, seems like it's quite common. People are saying I should disable sleep mode, but really????