When I launched piano of kinect_demo(http://www.ros.org/wiki/mit-ros-pkg/KinectDemos/Piano), I got error info as below:

tansir@ubuntu:~$ roslaunch piano pianist.launch ... logging to /home/tansir/.ros/log/603561ba-849b-11e1-b4ea-3859f96b708e/roslaunch-ubuntu-12805.log Checking log directory for disk usage. This may take awhile. Press Ctrl-C to interrupt Done checking log file disk usage. Usage is <1GB. started roslaunch server http://ubuntu:51147/

SUMMARY

PARAMETERS * /rosdistro * /openni_node1/use_indices * /openni_node1/depth_registration * /openni_node1/image_time_offset * /openni_node1/depth_frame_id * /openni_node1/depth_mode * /openni_node1/debayering * /rosversion * /openni_node1/projector_depth_baseline * /openni_node1/rgb_frame_id * /openni_node1/depth_rgb_translation * /openni_node1/depth_time_offset * /openni_node1/image_mode * /openni_node1/shift_offset * /openni_node1/device_id * /openni_node1/depth_rgb_rotation

NODES / openni_node1 (openni_camera/openni_node) kinect_base_link (tf/static_transform_publisher) kinect_base_link1 (tf/static_transform_publisher) kinect_base_link2 (tf/static_transform_publisher) kinect_base_link3 (tf/static_transform_publisher) handdetector (hand_interaction/detectskelhands) ressetter (dynamic_reconfigure/dynparam) skel_tracker (skeletal_tracker/tracker) finger_detector (hand_interaction/analyzehands) pianist (piano/pianist)

auto-starting new master process[master]: started with pid [12819] ROS_MASTER_URI=http://localhost:11311

setting /run_id to 603561ba-849b-11e1-b4ea-3859f96b708e process[rosout-1]: started with pid [12832] started core service [/rosout] process[openni_node1-2]: started with pid [12844] process[kinect_base_link-3]: started with pid [12845] process[kinect_base_link1-4]: started with pid [12846] process[kinect_base_link2-5]: started with pid [12848] process[kinect_base_link3-6]: started with pid [12856] process[handdetector-7]: started with pid [12868] process[ressetter-8]: started with pid [12879] process[skel_tracker-9]: started with pid [12883] process[finger_detector-10]: started with pid [12885] process[pianist-11]: started with pid [12891] Hold Hand .7 meters from the kinect, fingers out, palm facing the sensor. Waiting for service /openni_camera/set_parameters... terminate called after throwing an instance of 'openni_wrapper::OpenNIException' what(): unsigned int openni_wrapper::OpenNIDriver::updateDeviceList() @ /tmp/buildd/ros-diamondback-openni-kinect-0.2.1/debian/ros-diamondback-openni-kinect/opt/ros/diamondback/stacks/openni_kinect/openni_camera/src/openni_driver.cpp @ 109 : enumerating image generators failed. Reason: Can't create any node of the requested type! [openni_node1-2] process has died [pid 12844, exit code -6]. log files: /home/tansir/.ros/log/603561ba-849b-11e1-b4ea-3859f96b708e/openni_node1-2.log InitFromXml failed: Can't create any node of the requested type! [skel_tracker-9] process has died [pid 12883, exit code 29]. log files: /home/tansir/.ros/log/603561ba-849b-11e1-b4ea-3859f96b708e/skel_tracker-9.log respawning... [skel_tracker-9] restarting process process[skel_tracker-9]: started with pid [13038] ^C[pianist-11] killing on exit [finger_detector-10] killing on exit [skel_tracker-9] killing on exit [handdetector-7] killing on exit [kinect_base_link3-6] killing on exit [kinect_base_link2-5] killing on exit [kinect_base_link1-4] killing on exit [kinect_base_link-3] killing on exit [ressetter-8] killing on exit [rosout-1] killing on exit [master] killing on exit shutting down processing monitor... ... shutting down processing monitor complete done

Who can tell me what's wrong with it,thanks a lot!