I am putting a fix in the cvs directory
http://cvs.math.utexas.edu/cgi-bin/cvsweb.cgi?cvsroot=maxima
See bin/xmaxima
If you get a new xmaxima then it should work correctly if either the
window manager shuts it down with a 'delete' or if you use either of
the 'exit' menus on xmaxima. Note I believe the MS windows version was
correct, and this got broken in making the windows version ...
william
ps: However if you just destroy the xmaxima or kill it with a
signal, then the maxima process is still left running and needs to be killed
with a signal. I should fix that too .. but later.