[winGRASS] negative kappa values through r.kappa

[Todd Buchanan]

I recently used r.kappa to produce an error matrix for a Landsat ETM+ 
image that I classified.  The classification is right on, but I seem to 
be getting negative kappa values.  Also, %commision and %ommision are 
100.0%.  Does anyone have suggestions on why kappa values might be 
negative or can anyone help interpret the error matrix?

thanks,

todd