Strange thing in Maxima: reduction of fraction

>>>>> "Leo" == Leo  <sdl.web at gmail.com> writes:

    Leo> On THU, 7 DEC 2006, Jihuan. T. wrote:
    >> Hello everybody!
    >> 
    >> I've run across such an odd thing:
    >> 
    >> (%i1) (p - q) / abs(p - q)^2;
    >> 
    >> p - q
    >> (%o1)                              --------
    >> 2
    >> (q - p)
    >> 
    >> (%i2) (q - p) / abs(q - p)^2;
    >> 
    >> 1
    >> (%o2)                                -----
    >> q - p
    >> 
    >> Obviously, the output of (%o1) is correct, because I've not made any 
    >> assumptions about p & q in advance. However, why did Maxima produce the 
    >> output of (%o2) when I swapped the order of p & q as in the above?
    >> 
    >> Thanks a lot!

    Leo> Looks like a bug.

Is it?  Maxima doesn't always simplify everything that you type in.
Isn't %o2 correct, independent of any assumptions on p & q (except
that I think maxima is implicitly assuming p and q are real)?

Ray