KDM hang after login

[Jonathan Byrne <jonathan@yamame.org>]

Over the weekend I upgraded my desktop system to KDE 3.2.1 (from 3.1.5)  and 
did the same on my Thinkpad this morning.  Everything seems to be working 
fine except for one puzzling problem.  After logging in via kdm, it gets as 
far as the default KDE background and then just stops, with nothing on-screen 
except the background.  It does it on both machines, so I guess it can be 
called duplicatable.

My temporary workaround is to use gdm and select a KDE session, which works 
without a hitch.

The kdm version is 3.2.1-1, on Sid.

Has anyone else seen/solved this problem?

TIA,

Jonathan Byrne