basic control systems examples in Matlab and Mathematica. Question on impulse reponse using transfer function in Mathematica

hi;
Any one out there by any chance uses the Mathematica control systems toolbox? V2.02?
I am trying to learn how to use it by implementing Matlab
control systems basic problems in Mathematica.
I am getting a problem when I try to obtain the impulse response using a transfer function as the system representation.
I get no such problem when I implement the same example in Matlab.
I was wondering if any one can check this example and who might be using this package who could tell me what is wrong.
I have the complete examples on my web page.
The link to this one specific example is here
http://12000.org/my_notes/mma_matlab_control/mim/node18.html
to see the error, scroll to the bottom of the page.
It is the example titled
"How to display the response to an impulse of an underdamped, critically damped and over damped system?"
And the complete document with more examples can be found here
http://12000.org/my_notes/mma_matlab_control/index.htm
It is hard to get help on this since it does not seem many people use Mathematica for control systems even though I think there is an advantage to using a symbolic system for solving control systems problems as it allows easy coupling between the mathematical modeling phase (the analytical part) and the design phase (where more emphasis is on the numerical part).
I also think the Mathematica documentation for this package could be improved.
Nasser
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