After upgrading my laptop to the latest of the latest and even recompiling pretty much the whole system after that, I was still facing a whacky system which crashed on me on seemingly random times.
After a while I noticed that when I log in, hit alt+F2 and fire up 'konsole', the whole X server comes down crashing on me. Resulting in a few seconds of dark terror and a fresh login panel.
After running konsole from a text terminal, I spotted the following errors:
kdeinit4: preparing to launch /usr/bin/konsole konsole(2671): Attempt to use QAction "change-profile" with KXMLGUIFactory! Undecodable sequence \001b(hex)[?1034h
Because any attempt to trace the program failed, I started to search for other people and their solutions.
I've read things about people reinstalling parts of Xorg (namely libX11 as 1.1.5 seems to have some quirks) and parts of Qt 4.5 which should be unstable as well. None of these things worked for me and after restoring the system in the unmodified state, I found someone claiming that removing 'tweaks' in the xorg.conf file for the nVidia driver did the trick.
Although I indeed upgraded the nvidia-drivers package, I thought this was one of the bogus stories (like people solvin mounting problems by unplugging printers on the other side of the globe) - but at this point I had nothing to lose.
To my sheer terror I must admit that it actually worked!
I've had one occasion where konsole started but the window rendering was all screwed up (white or no background or no window decorations) but I hadn't linked it to the display driver itself.
For now, everything is stable so I assume that I found the culprit. Please note that one or more of the following will make your KDE 4.2.2 desktop crash randomly:
I have 2 options left in my configuration which are there for a while now and which still seems to be perfectly safe:
Hopefully this post will safe someone a lot of grey hairs and a couple of precious hours spent on a goose hunt...