Imagemate USB3 card reader with Canon 5D Mark III

I have been using my reader with a CF card Ultra II/2.0 GB, along with my Macbook Pro OS X 10.8.3, for more than 2 years with my Canon 7D. No problem whatsoever. I recently bought a Canon 5D Mark III and it won’t recognize the files recorded on it. When the reader doesn’t simply crash, Lightroom (4.4) or Photoshop CS6 tell me that they don’t recognize the files. If I plug the Canon directly on my computer, it works just fine.

I have searched for a firmware update but did not find any. 

Any help would be much appreciated.

Denis