Users of the CWRU ROS mirror, In keeping with recent changes in the ROS package sources, the mirror URL for the CWRU mirror has changed. Please change your old URL in * /etc/apt/sources.list.d/ros-latest.list* as follows: from: http://mobilerobots.case.edu/mirror/code.ros.org/packages/ros/ubuntu to: http://mobilerobots.case.edu/mirror/packages.ros.org/ros/ubuntu I've updated the mirrors page at http://www.ros.org/wiki/ROS/Installation/UbuntuMirrors to reflect these changes as well, so you can also refer to that page for the proper URL for your distribution. With these changes, the CWRU mirror is once again mirroring the latest ROS packages, including the .debs for Natty as well as the Electric betas. - Eric