FaceTime and AppleID

When I attempt to use FaceTime on my laptop (OS X) it requires me to sign up with my AppleID. I enter the details and I am offered a popup:

App-Specific Password Required

Your Apple ID is protected with two-step verification. You must generate an app-specific password at appleid.apple.com to sign in.

This is fine. I am taken to by AppleID account and am invited to generate an app-specfic password. It offers the app name as 'iMessage and FaceTime' that I am happy to accept. It then offers a password that I also accept.

However I am still not logged into FaceTime. I am still invited to enter my AppleID and password. When I do this I go round again, being asked to generate an app-specific password. (In my AppleID settings show this app in its history)

Any ideas about how I can get further?