On the irreducibility of the two variable zeta-function for curves over   finite fields
  In [P] R. Pellikaan introduced a two variable zeta-function for a curve over a finite field and proved that it is a rational function.   Here we show that its denominator is absolutely irreducible. This is motivated by work of J. Lagarias and E. Rains on an analogous two variable zeta-funtion for number fields. 
Niko Naumann