Do the controls in Skyward Sword use the LEDs on the Dolphinbar or just the motion sensor? It sounds like the LEDs may have failed (I had a similar problem). Take a photo with a digital camera and see if you can see them.
Windows 7 x64
i5 2500K @4.6Ghz
8GB DDR3 1600
Nvidia GTX 660Ti
i5 2500K @4.6Ghz
8GB DDR3 1600
Nvidia GTX 660Ti
