Jaunty: Kde silently dies during startup

[b0rland]

After a dist-upgrade on 15.04.09 at about 7:00 AM GMT, kde started dying during startup. X server loads fine, kdm also works. After choosing "kde" session and logging in, a usual splash screen with gradually appearing icons is displayed; immediately after second and third icons fade in, the screen goes blank and I get back into kdm login screen. I can still successfully log into other window manager (namely fluxbox) from kdm.

Latest messages in xsessions-errors are:
qUncompress: Input data is corrupted
ksmserver(5153): stream is bad :-( status= 2
startkde: Shutting down...
klauncher: Exiting on signal 1
startkde: Running shutdown scripts...
startkde: Done.
kded4: Fatal IO error: client killed

Attached are ~/.xsession-errors, a piece of dpkg.log for today's morning update.

[b0rland (b0rland)]

With compositing turned off in xorg.conf KDE loads fine

[Jonathan Thomas (echidnaman)]

Could you attach a copy of /var/log/Xorg.0.log and /var/log/Xorg.0.log.old after a failed startup please? The output of the command "lspci -vvnn" (two v's, not a w) would also be very helpful. Thanks in advance.

[b0rland (b0rland)]

Well... Switching compositing off and back on somehow magically solved the problem and I can't reproduce it now.
Just in case, attaching the output of lspci -vvnn as requested.

[Jonathan Thomas (echidnaman)]

It was most likely a driver bug causing X to crash, but without the X logs there's not much to be done. :(

Anyway, thanks for reporting the bug, and I'm glad it worked out for you.

[Gerardo Contreras (gera-gera)]

I'm having this same problem right now. Compositing is disabled. It seems it happens when loading ksmserver. I started a fail safe session, then loaded plasma, and everything loaded ok, except by ksmserver which crashes in the same way.

[Jose Bernardo (bernardo-bandos)]

I have also been bitten by this bug. Launching a kde session from kdm dies after the third icon, launching starkde from a failsafe session works. I have a nvidia GeForce 8400GS, if you want I can post the full lspci --vvnn. I tried removing my .kde and starting, and the .xsession-errors file is from that try.

The relevant part of my lspci:
01:00.0 VGA compatible controller [0300]: nVidia Corporation GeForce 8400 GS [10de:0422] (rev a1)
        Subsystem: ASUSTeK Computer Inc. Device [1043:8254]