[CentOS] FreeNX authenticates but no desktop on centos 5 ??

a final-final note (and then I'll really clam up, promise!): I just tried to
connect from an nxclient running on windows (an intel mac runing windows in
bootcamp), and got the same thing: the nxclient authenticates but no desktop
when the nxserver is on centos 5, whereas it conects fine to centos 4.4 as
the nxserver (here with x-win32 as the X11 window running on the client
side).

so to recap, my little issue (freenx authenticates but no desktop, on a
centos 5 but not a centos 4 machine as nxserver) happens from both mac and
windows nxclient. I think this narrows it down to something about my centos
5 nxserver (that machine), and something that is not: the firewall or
SELinux (same thing with the firewall disabled & selinux permissive), gnome
(the console and vnc give me a clean gnome session with the same user
account), authentication key issues (authenticates just fine), a specific
user account (same for new account), or ssl encryption (enabled), run level
or ssh forwarding (these are not supposed to matter much; I'm at run level 5
with ssh forwarding enabled).
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.centos.org/pipermail/centos/attachments/20070428/e5b4b754/attachment-0001.html>