I have a Mac Pro running Mac OS 10.8.2. Apparently I'm not good at properly ejecting USB or CF memory devices. I have some that when inserted produce the "Improperly Ejected" error and cannot be opened (or sometimes only open for a few seconds). So now I have some CF cards and USB drives that can be read on Windows, will operate in a digital camera, but can't be read by my Mac. Is there a way to fix the devices once they have apparently been damaged in this way ? UPDATE: I noticed that if the CF card (plugged into my external USB card reader) is inserted while the Mac is powered off, then I power / boot up, the card is fine... no error message. Same with USB memory sticks. Otherwise, most of my CF cards or USB sticks get the Improperly Ejected error. What does this mean ?