parGosper from zeilberger package doesn't work as expected

Hi,

I have the following test for parGosper,which seems not to work.
I think i have interpreted the documentation correctly.

res below should vanish identically.
I have attached my maxima file and an output file.

Andre

---- testparGosper.max ----
display2d : false;

load(zeilberger);

F(d,a1,k1,a2,k2,b2,l2)
     := 1/(a1-k1)!/k1!*(-1)^k1
         /(a2-k2)!/k2!*(-1)^k2
         /(b2-l2)!/l2!*(-1)^l2
         *(a1+2*a2+k1+d-1)!
         /(a1+2*a2+k1+d)!
         *(a1+a2+k1+k2+d-1)!
         /(k2+d-2)!
         *(b2+l2+d-2)!/(l2+d-2)!
         *(k2+l2+d-2)!/(k2+l2+d-1+k1)!;

h : parGosper(F(d,a1,k1,a2,k2,b2,l2),b2,l2,0);

R(d,a1,k1,a2,k2,b2,l2) := h[1][1];
A0(d,a1,k1,a2,k2,b2,l2) := h[1][2][1];

res : A0(d,a1,k1,a2,k2,b2,l2)*F(d,a1,k1,a2,k2,b2,l2)
     - (R(d,a1,k1,a2,k2,b2,l2+1)*F(d,a1,k1,a2,k2,b2,l2+1) - 
R(d,a1,k1,a2,k2,b2,l2)*F(d,a1,k1,a2,k2,b2,l2));
res : factor(minfactorial(res));

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