Yep. I agree with Dual Monitors suggested by Starwarsman.
If that doesn't do it... uninstalling the previous vid card drivers could do it.
But i'm quite sure it's the Dual Monitor issue!
If you try popping up the display properties panel to fix this probem and it doesn't show, then you'll have to plug another monitor in and select single monitor usage.
This happened to me with my laptop when i used dual monitors, it went hybernating and then shut down. When i restarted later on, without the dual monitor, all i had was barrytibbles issue. Had to plug another monitor, change to single display and that was it...
Starwarsman is right!