OK so I've tried turning off the v sync in game and forcing it on the nvidia control panel but I'm still getting the tearing. I'm using a GTX 580, but on the nvidia control panel I don't see anything that lets me choose application specific behaviour.
The best I can find is this:
http://i.imgur.com/e20KaOn.png
Where I've set the refresh rate to 60 and told it to override the scaling mode, but the scaling mode isn't the refresh rate so I guess it's not overriding that.
Is there something else I have to do?