Having trouble running pr2 kinematics tutorial

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I'm running ROS Fuerte, and cannot get arm_navigation forward kinematics working. Running with

roslaunch pr2_gazebo pr2_empty_world.launch

export ROBOT=sim
roslaunch pr2_3dnav right_arm_navigation.launch

like it is described in the tutorial (Forward kinematics for the PR2 arms; I cannot link to it). If I try to call

rosrun pr2_arm_navigation_tutorials get_fk

the process dies. The arm_navigation terminal provides the following error message:

[pr2_right_arm_kinematics-10] process has died [pid 8283, exit code -11, cmd /opt/ros/fuerte/stacks/pr2_kinematics/pr2_arm_kinematics_constraint_aware/bin/pr2_arm_kinematics_constraint_aware __name:=pr2_right_arm_kinematics __log:=/home/paturdc/.ros/log/c33d8246-cc75-11e3-a881-485d609d4113/pr2_right_arm_kinematics-10.log].
log file: /home/paturdc/.ros/log/c33d8246-cc75-11e3-a881-485d609d4113/pr2_right_arm_kinematics-10*.log

I didn't change anything in this stack. Is it a bug? Is there some setup step that I've skipped?

Anyone heard of this problem before???