error in xcorr2

[Jorge Alliende]

Hi there, 

Sorry for the noise, but I want to user xcorr2 and I get an error. I am using

GNU Octave, version 3.6.1

Octave was configured for "i686-pc-mingw32".

running on windows 7

has this warnings at the start
warning: gmsh does not seem to be present some functionalities will be disabled
warning: dx does not seem to be present some functionalities will be disabled
warning: function C:\Octave2\Octave3.6.1_gcc4.6.2\Octave3.6.1_gcc4.6.2\share\octave\packages\statistics-1.1.0\fstat.m shadows a core library function

to try xcorr2 I made 

x=rand(8,8)
y=rand(8,8)
z=rand(4,4)

[r,lags]=xcorr(x,y,'coeff')
[r,lags]=xcorr(x,z,'coeff')

and I get 
error: element number 2 undefined in return list.

II would appreciate any help. May be its a bug and I should send this to another place,
Thanks in advance
Jorge