this has the flat usb end that fits in the Air and the other end of the cable fits in the reader == I haven't used this reader before on this machine but have on others = I tried to connect the 50D directly to the USB ports using the same cable and Aperture never recognized it at all. The cable works, as when I plug the reader into the Air using that cable the power light comes on and the other light [showing that the accessing I think] -- lights up...but whether I use the reader or the camera, Aperture and Image Capture are not seeing the card
IME, the lights on the card readers often light up even when a card is not being read (afaict).
I'm going on the assumption that the problem occurs because of one of:
- the usb port
- the cable
- the reader
- the card
You seem to have ruled out the first three. (Not the reader positively, but the problem occurs even with the reader removed from the chain.) Does the set-up work with a second CF card?
Fwiw, IME the card-reader is by far the most prone to failure of the items listed above.
Thanks so much for your guidance [love the images on your Profile page by the way!] -- I'm starting to think it's the USB ports but two of them??? I needed to plug in my FitBit dongle to sync data and it was not recognized on either the L or R port. So it may be the ports are bad or something. I find it odd that both would go bad but will check and see. Thanks for the explanation and I'll sort it out and report back if I can figure it out = I do agree that card readers frequently fail [but then they are cheap so it's not a major issue usually] - I just hope my applecare on this machine is good still!