Why is reshape being called with two different numbers
of arguments? Is this expected?

I'll guess: reshape(x,y,w,h) in JComponent (JPanel superclass) and reshape(GLAutoDrawable, x,y,w,h) in GLEventListener.

A segfault is always bad news (and hard to pin on Jython --- whoever is making your JVM might be interested in a bug report), but JOGL is very low level some times, depending on drivers, I have been able to give you a page of Python that locks up a machine.

best of luck,