I noticed that processing's scale() command had some undesirable side effects on my gl normals. I created a obj loader and was testing it with a model I created in Maya.  When i imported the geometry it was tiny so i scaled it with processing's scale() command. here's some pertinent code:

void draw(){
 scale(100);
 pgl.beginGL();
 treeFrog.iaDraw(); // obj draw method using indexed arrays
 pgl.endGL();
}

The model loaded and scaled fine but wasn't lit correctly.  I spent a great deal of time debugging my code and found out that if i didn't scale the object it would be displayed correctly. It looks like scale() is not only scaling the geometry but also the normals. I'm not sure if this is a bug or just something i'm ignorant about. I generally stick with gl commands when working with gl geometry, but i was just running a quick test and figured it wouldn't make a difference.... wrong!  Anybody care to clarify this?

ok... to answer my own question, this isn't a processing issue.. gl.glScalef also scales the normals and messes up the lighting.  So if you scale an object you have to make sure to normalize the normals.  

gl.glEnable(GL.GL_NORMALIZE);

This slows things down though, so a better solution is to not use either scale() or gl.glScalef() and instead just manually scale the verticies.