Starting the Turtlebot on 11.04 as a non turtlebot user

edit

After having followed the setup instructions:

http://www.ros.org/wiki/Robots/TurtleBot/diamondback/Robot%20Setup
http://www.ros.org/wiki/turtlebot/Tutorials/Networking%20Setup

I'm attempting to start the turtlebot service,as suggested here:

http://www.ros.org/wiki/turtlebot_bringup/Tutorials/TurtleBot%20Bringup

But no such service can be found. There is a file called

/usr/sbin/turtlebot-start

and when I run this I get:

/usr/sbin/turtlebot-start: line 28: setuidgid: command not found

I'm running Ubuntu 11.04, and have installed the electric rather than the diamondback version (ros-electric-turtlebot-robot).

Any ideas on what's going wrong?

[Supplemental]

If I do the following:

sudo apt-get install daemontools setuidgid

Then edit /usr/sbin/turtlebot-start and change "turtlebot" in the setuidgid command to a valid user then I am able to run this script. However, I then get:

Failed to open port /dev/ttyUSB0.  Please make sure the Create cable is plugged into the computer.

The create base is switched on and the cable is connected. I can see that /dev/ttyUSB0 does exist.