Tdm starts as usual.
Login with password proceeds as normal until ksplash gets to the desktop icon, 'Loading the desktop'. The login appears to hang there. Clicking on the splash screen makes it close.
The background has not changed from the tdm background. There is nothing on the screen apart from the cursor and the background.
No input actions result in any action apart from Alt-Ctl-F(1-6).
Got out to a terminal prompt and logged in as root.
There are no errors in /var/log/tdm.log apart from the following:
[     0.70 ] error    3 BadWindow    request   20 minor    0 serial    500: "BadWindow (invalid Window parameter)"
[     0.73 ] error    3 BadWindow    request   15 minor    0 serial    501: "BadWindow (invalid Window parameter)"
[     0.74 ] error    3 BadWindow    request   20 minor    0 serial    528: "BadWindow (invalid Window parameter)"
[     0.74 ] error    3 BadWindow    request   15 minor    0 serial    529: "BadWindow (invalid Window parameter)"
[    12.56 ] error    3 BadWindow    request   20 minor    0 serial   1250: "BadWindow (invalid Window parameter)"
[    12.56 ] error    3 BadWindow    request   15 minor    0 serial   1251: "BadWindow (invalid Window parameter)"

ps ux logged in as my user reveals following processes:
martin@nede1:~$ ps ux
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
martin    9567  0.0  0.0   1936   608 ?        Ss   19:59   0:00 /bin/sh /opt/trinity/bin/starttde
martin    9614  0.0  0.0   3872   216 ?        Ss   19:59   0:00 /usr/bin/ssh-agent /usr/bin/dbus-launch --exit-with
martin    9617  0.0  0.0   3516   504 ?        S    19:59   0:00 /usr/bin/dbus-launch --exit-with-session /opt/trini
martin    9618  0.0  0.0   3228   396 ?        Ss   19:59   0:00 /usr/bin/dbus-daemon --fork --print-pid 5 --print-a
martin    9667  0.0  0.1  33364  3976 ?        S    19:59   0:00 dcopserver [tdeinit] --nosid --suicide
martin    9672  0.0  0.3  34664  8108 ?        S    19:59   0:00 kded [tdeinit] --new-startup
martin    9684  0.0  0.1  33696  3552 ?        Ss   19:59   0:00 [tdeinit] tdeinit Running...
martin    9687  0.0  0.3  34896  7064 ?        S    19:59   0:00 tdelauncher [tdeinit] --new-startup
martin    9693  0.0  0.3  24920  7728 ?        S    19:59   0:00 /opt/trinity/bin/tdeinit_phase1
martin    9694  0.0  0.0   1936   512 ?        S    19:59   0:00 sh -c kwrapper ksmserver --windowmanager twin
martin    9695  0.0  0.0   1844   244 ?        S    19:59   0:00 kwrapper ksmserver --windowmanager twin
martin    9697  0.0  0.4  35288  8428 ?        S    19:59   0:00 ksmserver [tdeinit] --windowmanager twin
martin    9698  0.0  0.4  36380  9404 ?        S    19:59   0:00 twin [tdeinit] -session 10d7cfd7da00013789259650000
martin    9699  0.0  0.4  31692  8596 ?        S    19:59   0:00 /opt/trinity/bin/kdesktop
martin    9700  0.0  0.3  45024  8132 ?        Sl   19:59   0:00 /opt/trinity/bin/kdesktop
martin    9702  0.0  0.5  35364 11048 ?        S    19:59   0:00 /opt/trinity/bin/kdesktop_lock --internal 9700
martin    9714  0.0  0.1  19992  2476 ?        S    20:01   0:00 sshd: martin@pts/1
martin    9715  0.0  0.1   7240  2596 pts/1    Ss   20:01   0:00 -bash
martin    9900  0.0  0.0   6044  1020 pts/1    R+   20:44   0:00 ps ux


Any ideas? Is the kdesktop_lock the problem?