moveTo() is used once, from what I can tell:
p.moveTo( q.position().x() +randomX, q.position().y() + randomY, 0 );

The object p is defined here:
Particle p = physics.makeParticle();

Which comes from this:
ParticleSystem physics;

So the problem is with the Traer Physics code.

Looking at:
http://www.cs.princeton.edu/~traer/physics/

We see the following right near the top:
"Changes since the previous version
Methods setVelocity, moveTo and moveBy are gone. Instead use:
position().set( float x, float y, float z )
velocity().set( float x, float y, float z )
position().add( float x, float y, float z )
velocity().add( float x, float y, float z )"

Thus, I suggest you try changing the line:
p.moveTo( q.position().x() +randomX, q.position().y() + randomY, 0 );

To:
p.position().set( q.position().x() +randomX, q.position().y() + randomY, 0 );