Did you install it manually, or through the "More Applets" function? Also, did you restart Cinnamon after it installed?
Note that if you went to Cinammon Spices online and downloaded/installed it manually, you may have gotten the older applet that won't work in Cinnamon 2.
HP Pavilion 17 Notebook, 8GB DDR3, 2.5GHZ A10-APU, Radeon HD 8650G
Registered Linux User #520972