In reply to jugpuller:
I had the same happen to me, and after 2 weeks it turned up it was something stupid like ticking a box in the laptop's graphics control panel.
I can't exactly remember what it was, but rings a bell that even though you select the second monitor to clone or dualview, you still need to tick a box that says something like "extend my desktop into this screen" which only shows when screen 2 is highlighted.
It may sound obvious, but it really wasn't obvious at all, and when it actually worked i could have sworn i had tried it before.
If that doesn't work then the hammer approach is the best option. It won't make it work, but is deeply satisfying.
Good luck