Shutdown request received

edit

hi,I am using laser assembler package for 2D pointCloud to 3D point-cloud conversion. First I am start launch file (laser.launch), then followed by I'll run cpp file, when I run .cpp file suddenly the roslaunch(master) file will be shutdown, the error is

[ WARN] [1375768306.726458068]: Shutdown request received.
[ WARN] [1375768306.726502466]: Reason given for shutdown: [new node registered with same name]

launch file is

<launch>
    <node pkg="laser_assembler" type="laser_scan_assembler" output="screen"  name="laser_scan_assembler">
    <remap from="/scan" to="tilt_scan"/>
    <param name="tf_cache_time_secs" type="double" value="11.0" />
    <param name="max_scans" type="int" value="400" />
    <param name="ignore_laser_skew" type="bool" value="true" />
    <param name="fixed_frame" type="string" value="/sr_lidar1_scan" />
  </node>
</launch>

thank you