Yes, it was the USB cable. My Stackshot didn't ship with one so I used an old one. Turns out it wasn't connecting. All sorted now.

Hi,
I just acquired a Stackshot 3X for my Canon 5DII. It took a while to get all the cables in the right place and for my Mac to play along. However, I'm stuck now. I can't activate Live View. The stackshot is recognised by HR, I can even trigger the shutter.
From memory, Live View settings on the ...