Comment 6 for bug 713478

I too see this problem, Express card for USB 3 support not recognizing devices. To add some more info, in my case when I booted the computer with the card in and the flash drive already plugged in I was able to look at the contents, format the drive, but I was not able to do much more than that. After unmounting the drive I was not able to remount it. Any information needed in addition to what is provided above I can give, just ask.