FXAA was already off.
Anti-Aliasing set to Application-Controlled for both Mode and Setting.
The in-game FSAA was off already too.
Got the bug (oh the darkness!!) when I died somewhere on ACT 3.
Also tried enable/disable FSAA ingame and nothing.
I guess i'll just revert back to 304 drivers.
Edit - Teleporting back to Bastion Keep fixed it for now. I will rollback the drivers asap.
Thanks for the help HGN