Problems with expandwrt



hello list,

here is a simple maxima session I've worked on:

(%i1) load(stopex);
Warning - you are redefining the Maxima function intersection
(%o1)    /home/matt/Works/maxima-5.9.3/share/simplification/stopex.mac
(%i2) eq: x*(a+b)+y*(c+d);
(%o2)                        (d + c) y + (b + a) x
(%i4) expand(eq);
(%o4)                        d y + c y + b x + a x
(%i6) expandwrt(eq,x);
(%o6)                        (d + c) y + (b + a) x

I installed maxima from the source code (O.S: debian GNU/Linux 3.1 
etch/sid, maxima-5.9.3.tar.gz,  clisp 2.38-6) and my questions are the 
followings:

1) Why did I receive that Warning?
2) I expected the following result from expandwrt function

(%o6)                        (d + c) y + b x + a x

but it seems my expandwrt doesn't work. Why?

thanks in advance !

matt