I tried Eclipse, and it seems to be pointing exactly the same places.

Synchronize is in javax.swing.JButton(java.awt.Component).enable() leading back up through awt and swing to org.jempeg.empeg.emplode.dialog.ProgressDialog.setStopEnabled() (line 161)

It would be neat if I could figure out how to export the stack backtraces.

I guess I'll start reading source.