The output from the command you gave me was 13C2. My graphics card is a GTX970, so Maxwell architecture if memory serves me. As far as I was aware the 396 driver should work fine.
I think you are on to something with the graphics driver though - I switched to nouveau then back to nvidia and the problem seems to have gone away. Not sure why that worked, but I'll go with it for now. I was intending on installing Steam and assumed that the Nvidia drivers would be better for that, but if the nouveau drivers work with it I'll happily switch.
Cheers for the assist though!