gauss chebychew quadrature in integration package

[Thomas Plehn]

http://img28.picoodle.com/img/img28/4/6/22/f_quadraturem_a5f90c3.png

hello,
I have tried to integrate a simple function in octave using the integration 
package.
the function is f(x,y)=x^2*sin(y)
the integration limits for both x and y are from 0 to 1.
the result should be (1-cos(1))/3 = 0,15323
this result is yielded by quadndg, gquadnd
but cquadnd yield a different result

should this be considered as a bug?