Using pdiff and itensor together



I'm trying to use pdiff with itensor and I've observed some strange
behavior.  If I try to differentiate a function of a tensor where the
argument and the differential have the same index, pdiff perfoms as
expected:

load(pdiff);
load(itensor);
diff(f(X([i],[])),X([i],[]));

output>   'kdelta([i],[i])*pderivop(f,1)(X([i],[]))

If the indices are different, then this is what I get:


diff(f(X([i],[])),X([j],[]));

output> 'diff(f(X([i],[])),X([j],[]),1)

Any help in resolving my errors or the inconsistent behavior would be
greatly appreciated.  Thanks,

Derek