[Help-gsl] wrong eigenvalues?

[Michael Gross]

Hello
(gsl 1.4, suse 8.2, make check is ok)

When I replace the Matrix in the example on 
http://sources.redhat.com/gsl/ref/gsl-ref_14.html#SEC235
with:
  double data[] = { 1, 2, 3,
                    4, 5, 6,
                    7, 8, 9};

(and replace the 4 in the gsl-calls with 3) then I get the eigenvalues:
18.8302, -3.15747 and -0.672768.

The polynom of the matrix is 18*l+15*l^2-l^3 so one eigenvalue has to be 0.
Matlab (and Maple) calculates (eig([[1 2 3];[4 5 6];[7 8 9]])) the 
eigenvalues 16.1168, -1.1168 and -0.0000.

What is wrong?

thx
  Michael