Importing photos from Canon 5D MK III

Just needing a little help. I have a new Canon 5D Mk III and ever since getting it I can not import the photos onto any software on my imac. I am trying to import them using the cable. I have tried through LR4 and the preview pictures come up with whats on my memory card but during the import mode it just freezes and then I get this message:

I have tried through Iphoto and the same thing happens and also through the Canon Software and the same thing happens. I have updated everything on my imac so I am running the latest versions of everything.

I have even tried using a card reader and it seemed to work fine the first time but now Im getting the same issues as above.

The strange thing is that it works fine on my partners macbook pro.

If anyone has any idea what could be cause this I would love to know!

Thanks