A regression in Maxima 5.17.1 with limits and assumptions?

Hi,

I noticed the following:

Maxima 5.16.3 http://maxima.sourceforge.net
Using Lisp CLISP 2.46 (2008-07-02)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) limit(a*sin(x)/x, x,0);
(%o1)                                  a


In contrast 5.17.1:

Maxima 5.17.1 http://maxima.sourceforge.net
Using Lisp CLISP 2.46 (2008-07-02)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) limit(a*sin(x)/x, x,0);
Is  a  positive, negative, or zero?

positive;
(%o1)                                  a



Two more things while I am poking around here:


(%i2) forget();
(%o2)                                 []
(%i3) limit(a*sin(x)/x, x,0);
Is  a  positive, negative, or zero?

zero;
(%o3)                                  a

Since I just told Maxima that a equals zero shouldn't it take that into 
consideration?


And also:

(%i4) forget();
(%o4)                                 []
(%i5) limit(a*sin(x)/x, x,0);
Is  a  positive, negative, or zero?

Now press CTRL-D and the question is repeated infinitely:

(%i5) limit(a*sin(x)/x, x,0);
Is  a  positive, negative, or zero?

Is  a  positive, negative, or zero?

Is  a  positive, negative, or zero?

Is  a  positive, negative, or zero?

Is  a  positive, negative, or zero?
<SNIP>

I admin it is a dumb thing to do :)

Cheers,

Michael