Bug#465939: Crashes often when changing virtual desktop in KDE with translucencies
Please note that I do not know how to reproduce the bug, it just happens. Sometimes I had it more than twice in the same day, other times I can be working for a week without the crash.
I think the crash is favoured when the virtual desktop I am switching to has a window whose content is changing at this moment, but I am not sure.
So, what do I have to do? To manually launch gdb and wait until a crash happens?