[ODE] Question on angular motors

[mike polyakov]

Hi,
  I'm trying to empower a virtual creature by adding AMotor joints to ball 
joints as the documentation suggests.  However, after setting all the
axes, etc, i cannot get the motor to actually provide any motion!  There is 
also no example of it being used in the test cases.  Can anyone suggest 
what i might be forgetting to do or provide a simple example (preferably in 
the dAMotorUser mode).  Without amotors, controlling this guy is going to 
be a lot tougher...
thanks!
mike