Version:            (using KDE 4.0.1)
Installed from:    Ubuntu Packages
OS:                Linux

This report was submitted to Kubuntu (https://bugs.launchpad.net/ubuntu/+source/kdebase/+bug/184448)

I guess I have the same issue here. Got a new machine w/ Ubuntu preinstalled (from Dell :-) and obviously wanted to change the host name. Did so directly in /etc/hostname (where else?).
After some more time (and several reboots), I installed the KDE4 packages available from:
     deb http://ppa.launchpad.net/kubuntu-members-kde4/ubuntu gutsy main
I'm having Ubuntu 7.10 (Gutsy Gibbon) obviously. Installation went fine.
When I try to login from GDM I always get the same error upon login:
 - KDE4 splash screen starts
 - Upon the fourth (or so) icon, I get a crash report behind the splash screen
 - Clicking into the splash closes it
 - The crash report informs me that ksmserver crashed
 - Closing the crash report, logs me out again and brings me back to GDM
Any ideas? Help is greatly appreciated!
For your info:
 I'm running on a Dell XPS M1330 w/ intel x3100 graphics card ("Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller"). Running the "intel" driver.
My hostname was something like "dell-laptop" or so and I changed it to "bartimäus" (note the umlaut).
ciao, daniel :-)

I installed the appropriate debug packages now and captured a backtrace: 
 
 ---------- snip ---------- 
 Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1". 
 [Thread debugging using libthread_db enabled] 
 [New Thread -1239562560 (LWP 6628)] 
 [KCrash handler] 
 #5  0xb7dd8749 in vfprintf () from /lib/tls/i686/cmov/libc.so.6 
 #6  0xb7de1902 in fprintf () from /lib/tls/i686/cmov/libc.so.6 
 #7  0xb7f02a97 in write_iceauth (addfp=0x0, removefp=0x0, entry=0x80c8330) 
     at /build/buildd/kdebase-workspace-4.0.1/ksmserver/server.cpp:346 
 #8  0xb7f02d8f in SetAuthentication (count=3, listenObjs=0x80c6ea0, 
     authDataEntries=0xb7f20ee8) 
     at /build/buildd/kdebase-workspace-4.0.1/ksmserver/server.cpp:422 
 #9  0xb7f03d69 in KSMServer (this=0x80c65f0, windowManager=@0xbfcbf5c4, 
     _only_local=false) 
     at /build/buildd/kdebase-workspace-4.0.1/ksmserver/server.cpp:664 
 #10 0xb7f008c9 in kdemain (argc=1, argv=0xbfcbf754) 
     at /build/buildd/kdebase-workspace-4.0.1/ksmserver/main.cpp:240 
 #11 0x08048582 in main (argc=-1208891278, argv=0x80c75f0) 
     at /build/buildd/kdebase-workspace-4.0.1/obj-i486-linux-gnu/ksmserver/ksmserver_dummy.cpp:3 
 #12 0xb7db1050 in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6 
 #13 0x080484f1 in _start () 
 #0  0xffffe410 in __kernel_vsyscall () 
 ---------- snip ---------- 
 
Thanks