On Mon, May 17, 2010 at 2:42 AM, Andreas Vogt
<andreasv@informatik.uni-bremen.de> wrote:
> [ERROR] 4.264000000: Client [/move_base] wants topic /base_laser to have
> datatype/md5sum
> [sensor_msgs/PointCloud/d8e9c3f5afbdd8a130fd1d2763945fca], but our
> version has [sensor_msgs/LaserScan/90c7ef2dc6895d81024acba2ac42f369].
> Dropping connection.

hi Andreas,

That error usually indicates an inconsistent or incomplete build,
where one part of the tree was built with an older message definition.
 Have you tried to 'rosmake' all packages that you're using?

	brian.