Fred,

Sounds like you are connecting your camera to the Mac to download images. Although that should work, most pros recommend (and I agree) that it works much better to use an external card reader instead of the camera’s built-in USB port cabled to the Mac. An external reader is usually much faster at transferring images.

I’m not sure what could be wrong with doing it in-camera. Have you tried resetting everything (Restart Aperture, if that doesn’t help restart the computer and camera) and have you tried a different cable in case it is just a coincidence that you have a failed cable at the same time you upgraded the 7D firmware?

When you connect the 7D to the Mac, does it appear in the Finder’s devices list as a volume?

Try checking system information to see if the camera shows up on the USB bus when plugged in. Hold down option and click the Apple menu and select System Information. Then click USB in the left column to see a list of devices connected to the USB bus.