problem updating simulator_gazebo1.7.6 in a overlay

edit

Hello, i'm trying to update my simulator gazebo to fix the contact sensors problem, i'am working with ubuntu 12.04 and ROS fuerte, i'm following the Overlay_intallation, but when i try to update the repository i obtain this:

jose@ubuntu:~/fuerte_workspace/sandbox$ rosws set simulator_gazebo --hg https://code.ros.org/svn/ros-pkg/stacks/simulator_gazebo/tags/simulator_gazebo-1.7.6/simulator_gazebo

     Add new elements:
  sandbox/simulator_gazebo      hg  https://code.ros.org/svn/ros-pkg/stacks/simulator_gazebo/tags/simulator_gazebo-1.7.6/simulator_gazebo   

Continue: (y)es, (n)o: y
Overwriting /home/jose/fuerte_workspace/.rosinstall

Do not forget to do ...
$ source /home/jose/fuerte_workspace/setup.sh
... in every open terminal.
Config changed, remember to run 'rosws update sandbox/simulator_gazebo' to update the folder from hg
jose@ubuntu:~/fuerte_workspace/sandbox$ rosws update simulator_gazebo
[sandbox/simulator_gazebo] Installing https://code.ros.org/svn/ros-pkg/stacks/simulator_gazebo/tags/simulator_gazebo-1.7.6/simulator_gazebo (version None) to /home/jose/fuerte_workspace/sandbox/simulator_gazebo
abort: HTTP Error 404: Not Found
Exception caught during install: Error processing 'sandbox/simulator_gazebo' : [sandbox/simulator_gazebo] Checkout of https://code.ros.org/svn/ros-pkg/stacks/simulator_gazebo/tags/simulator_gazebo-1.7.6/simulator_gazebo version None into /home/jose/fuerte_workspace/sandbox/simulator_gazebo failed.

ERROR: Error processing 'sandbox/simulator_gazebo' : [sandbox/simulator_gazebo] Checkout of https://code.ros.org/svn/ros-pkg/stacks/simulator_gazebo/tags/simulator_gazebo-1.7.6/simulator_gazebo version None into /home/jose/fuerte_workspace/sandbox/simulator_gazebo failed.

Anyone could help me???