Rosinstall: multiple ros stacks error

edit

I was just trying to create a new ROS workspace on a computer in our University network using rosws init but I'm getting the following error:

$ rosws init . /opt/ros/fuerte/
Using ROS_ROOT: /opt/ros/fuerte/
Writing /usr/wiss/kargm/work/ros/.rosinstall
(Over-)Writing setup.sh, setup.bash, and setup.zsh in /usr/wiss/kargm/work/ros
ERROR in rosinstall: Multiple ros stacks found in config set(['/opt/ros/fuerte/share/ros', '/work/ros/fuerte/share/ros']), Please elimate all but one.
They come from the following sources: {'/opt/ros/fuerte/setup.sh': '/opt/ros/fuerte/share/ros', '/work/ros/fuerte/share/ros': '/work/ros/fuerte/share/ros'}

Apparently the problem is that in our case the /opt/ros/fuerte links to /work/ros/fuerte which is a standard configuration on the university machines to save space on the system partition. Anyhow I am wondering why rosinstall is complaining about a second ros stack on /work/ros/fuerte since I could not find any reference to it in any .rosinstall-file or any other files in the ROS workspacs... So how is this "config set" (which is mentioned in the error message) build? And how can I eliminate one of the ros stacks (preferably while keeping my current setting)?