Rendering Thread Error

I am getting the following error.

net.java.games.jogl.GLException: Attempt to re-set or change rendering thread
      at net.java.games.jogl.impl.GLContext.setRenderingThread(GLContext.java:238)
      at net.java.games.jogl.GLCanvas.setRenderingThread(GLCanvas.java:162)
      at net.java.games.jogl.Animator$1.run(Animator.java:89)
      at java.lang.Thread.run(Unknown Source)

Can anyone gimme some feedback on what is going on?
Could it be that I have dual monitors?

-Zak