Reformatting the cards in the camera would not cause that. I always reformat in the camera after every import into Aperture. I'd looks at the MacBook. Have you applied any upgrades recently to either Aperture or the OS on your MacBook?
You might get more answers in the Apple Post Processing forum.
I've had problems (not on Mac) with antivirus software deciding to check every file that is opened, every time it's opened. That caused a huge slowdown until I turned it off for most of my discs & USB devices.
The problem with using the camera's USB connection is that the camera has a slow USB port, most card readers are faster, and the camera is forced to remain awake and the camera is not being powered by the computer but by the camera's battery so the transfer will fail if the battery goes dead.
Thu 08-Nov-12 07:20 PM | edited Sat 10-Nov-12 11:00 AM by luckyphoto
You might consider buying a good USB card reader. They're about $10-15. If you get good performance from that it may be a faulty USB cable or connectors are causing errors which are requiring re-transmissions.
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