Question: Analytical PDE solution

Hello,

I have found numerous ways of plotting PDEs, but I am trying to ask Maple to calculate the simple analytical solution of one.

Now, Maple is very happy to solve the following with one initial condition:

restart;
with(PDEtools);

pde := diff(u(z, t), t)+c*(diff(u(z, t), z)) = A;
IBC := (u(z, 0) = f(z));

sys:=[pde,IBC];

ans:=pdsolve(sys); 


However, when we take, 
IBC := (u(z, 0) = f(z), D[1](u)(0, t) = 0, D[1](u)(-h, t) = 0);

instead, (the initial condition, along with two boundary conditions du/dz evaluated at z=0 and z=-h, set to 0, but could be any number/simple function),
Maple will not calculate the answer, nor will it display an error message for me to work out where it is going wrong.

h is a positive integer and so are c and A. 

This is just a simple example. But I have seen the same method work fine for more complex PDEs so I don't know why it won't work for this one. Can anyone see where the problem is please?

Thanks and kind regards,
Emma