I\'ve installed the latest nvidia drivers (375.26) manually, and installed CUDA using cuda_8.0.44_linux.run (skipping the driver install there, since the bundled drivers are
Running
sudo apt-get purge nvidia-*
and reinstalling the drivers using
sudo apt-get install nvidia-375
solved it. Just for the record, the first time I updated the drivers using the GUI (Additional Drivers tab in Software & Updates).