Version:            (using KDE 4.2.0)
OS:                Linux
Installed from:    Gentoo Packages

This is a very strange bug. I'll try to write as much as possible.

0. Some time ago I ran 'kwin --replace', and then previous version of kwin was hanging as zombie process.

1. It started in the middle of my session; I haven't installed new pkgs or upgraded applets.

2. Eventually I've noticed that Konsole stops understanding ^keys, such as ^C ^Z. So if I start `ping localhost' and then hit ^C -- nothing happens. Ping remains pinging, and thats all. Er, actually "^C" is printed on the terminal, much like as it is incorrect binding, but it isn't:

$ stty -a
speed 38400 baud; rows 40; columns 157; line = 0;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
-parenb -parodd cs8 -hupcl -cstopb cread -clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon ixoff -iuclc -ixany -imaxbel iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke

3. The worst thing is that it's not only Konsole's fault. If I run xterm and run command there -- effect is exactly the same.

4. Neither xterm, nor console is not closing using X button in the window frame.

5. If I run "system activity" applet and try to close a window using popup menu "Send signal -> SIGTERM" it is not work (whereas SIGKILL does the thing).

6. I think, bug #185995 is related somehow.

7. This I now happening even after reboot!

8. It is all working in separate fluxbox session. I mean xterm is catching ^C ok there, so it isn't Xorg's fault imho.

9. Of course it is working in system console (Ctrl+Alt+F1)  :)

10. There is kwin_killer_helper zombie processis in my process list.

Well... hope if this helps somehow :\

P. S: All of this makes me think of incorrect SIGTERM handling or something... Seems that it is not achieving dest process (I know, it's a bit crazy to say that =).