Version: (using KDE 4.3.3) OS: Linux Installed from: Gentoo Packages When Alt+Tab is used to switch applications and then used very soon again, maybe before then new application has appeared, the keyboard is totally lost. It is necessary to close all applications with the mouse, log out, log in again, start all applications and open the documents. It happens about twice per week since the migration from KDE3 to KDE4. (Once the mouse buttons were lost too, so the system had to be shut down with the power button. Luckily this triggered some shutdown function, so that the filesystems were not damaged.)
*** This bug has been marked as a duplicate of bug 171685 ***