Using several machines, Firewire directly in to the machine, on an iMac, Power Mac, and Laptop
Running OSX 10.8.5 It was also a problem on 10.8.1 and 10.8.3.
At first I thought the cards were duplicating files because the same images kept being downloaded after I thought the card had been cleared. Then I discovered they were not deleting any of the files, no warning of any problem to my knowlege. If I put the same card back into a USB reader, they download and delete without a problem. I have several card readers and I was just going to trash them, but if you have a fix it would be great. The card reader is hard to find, and they do not sell them in the US. They do download cards quickly, but the delete issue is so severe the card readers are useless due to the volume of images we go through daily. Happy to send a sample reader if it helps.