I have also noticed the lack of
session types in kdm menu - only "default", "xfce" and
"failsafe" are present. After compiling and installation of
kde 3.5.10 all of the DE's I had installed were on the
list.
I haven't seen that problem exactly, but I ran into a similar problem. I was not
seeing Trinity as an option in the KDE 4 KDM. The cause was I had no copy of the
trinity.desktop file in /usr/share/apps/kdm/sessions, which is where the KDE 4 KDM looks
for those files. I updated my build script to ensure that file is installed in both
locations (/opt/trinity/share/apps/kdm/sessions).
Darrell