I inserted a SD card yesterday trying to grab some data from work. I also pop in my USB ext enclosure (an older one for IDE drive, I wonder that matters). At first I could not see the USB HDD but I had tried that drive the morning earlier so I knew that drive works for sure. I opened up Disk Utility and it doesn't even show up on the left hand column. As I thought there might be a problem... I was ejecting the SD card since I have done copying the work data. Poof! There it was! Right away I saw the HDD icon shows up on desktop. Anyone experienced this as well?