Make sure that you set the team number property on the camera viewer in the SmartDashboard. And make sure that you are running the SmartDashboard from the start menu not the Netbeans or Workbench version.
The SmartDashboard installed by the C++ or Java plugins won't offer the option to display the camera since it needs some more libraries to do the image capture and display. Have you installed it from the SmartDashboard project?
The latest release is the installer V1.04 and is available here:
http://firstforge.wpi.edu/sf/frs/do/...nstaller_1_0_4
and the directions for installing it are here:
http://wpilib.screenstepslive.com/s/...sion-installer
Be sure that the team number is set in the camera properties as described in the screensteps web page.
Brad