.xsession not being read?

[carlf@panix.com (Carl Fink)]

Thanks to everyone for the answers on installing KDE or GNOME on a
2.0 box.  I appreciate it.

Installing GNOME brought something to mind I hadn't thought about,
although I noticed it months ago:  my .xsession file is never read. 
I had to edit the global /etc/X11/Xsession file to force X to load my
window manager.  

This is irritating.  Why would .xsession not be read?  Any ideas?  I
have three Unix books and four Linux books here, and not one
describes the X startup process even well enough for me to figure out
which program actually reads Xsession and .xsession files.
-- 
Carl Fink		carlf@dm.net
"This fool wishes to reverse the entire science of astronomy." 
	-Martin Luther on Copernicus' theory that the Earth orbits the sun