diff doesn't work

diff(exp); doesn't work for anything but diff(x,x);
wich gives 1 (obviously)
From what I've heard it has to do with CLISP...
Is their a workaround?

Maxima version: 5.9.0
Maxima build date: 17:48 6/27/2004
host type: i386-unknown-openbsd3.5
lisp-implementation-type: CLISP
lisp-implementation-version: 2.32 (2003-12-29) (built
3297266576) (memory 3297340150)