Hi all, This isn't technically a macbook pro question but I thought more people would use ssd's here than in the imac forum. I currently boot my imac off a crucial m4 256gb ssd connected by thunderbolt through a seagate goflex adapter. I recently purchased a 512gb version of the same drive to replace it. I connected this drive to the imac using usb to sata caddy and formatted it hfs+ using disk utility. I then tried to do a full disc copy using CCC from the 256gb one. After that finished the drive appears to become corrupt and unusable. I tried formatting it in disk utility and it says 'Cannot write to last block of the device'. Windows cannot see it either. Interestingly, disk utility knows it's a 512gb m4 but just cannot do anything with it. Anyway, I sent it back and they sent another one and exactly the same thing has happened again. So it's gone back again and i'm now waiting for the third one which I am not planning to use CCC with. Has anyone had any similar problems / have any suggestions? A fresh install isn't the end of the world, just a bit annoying.