I am experiencing problems when trying to execute: roslaunch pr2armnavigationtutorials pr2floorobj_world.launch in my system ubuntu 12.04, ros fuerte.

error: ~$ roslaunch pr2armnavigationtutorials pr2floorobj_world.launch ... logging to /home/anshar/.ros/log/f502a8a2-c99b-11e2-8a53-5c260a08367a/roslaunch-anshar-17151.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.

while processing /opt/ros/fuerte/stacks/pr2simulator/pr2gazebo/pr2.launch: Invalid roslaunch XML syntax: [Errno 2] No such file or directory: u'/opt/ros/fuerte/stacks/pr2simulator/pr2gazebo/pr2.launch'

After checking using rospack find. The file it is in my ROS path. Thanks in advance.

Cheers