Version: (using KDE 4.3.5) OS: Linux Installed from: Ubuntu Packages Server grab is performed on kdm to avoid certain attacks. It can be easily bypassed just by opening nay menu (session chooser, for example). Then the X ungrabs the server. It can be tested opening a virtual keyboard (I tested with klavier, add it as "(sleep 2; klavier ) &" at /etc/kde4/kdm/Xsetup. It should not be usable, but if any menu is opened, it becomes usable.
hmpf. kdm "chases behind" qt to immediately re-grab the inputs once the popups are gone. this worked at some point, so maybe a newer qt broke it. is the ungrab really permanent or is there something you can do (other than restarting the greeter) to make klavier not work again?
works for me with qt 4.7.3, x server 1.9.99.901.
on kdm screen, either using mouse or keyboard to navigate menu->Shutdown results in a "T_urn of Computer" "R_estart Computer" "C_ancel" dialog that (still) cannot be controlled via keyboard. It's as if it lacks focus. Tested on Fedora 15 with qt-4.7.3, kde-4.6.3, x server 1.10.1
Per my comment to bug #268988 , adding to /etc/kde/kdm/kdmrc either: GrabInput=Always or GrabServer=true seems to help the immediate issue for me.