Version:            (using KDE KDE 3.4.2)
Installed from:    Debian testing/unstable Packages
OS:                Linux

I don't exactly remember what I was doing when kwin crashed, but it always happened when a swing dialog was open and I closed it or maybe tried to focus the dialog underneath... Here's the bt:

[KCrash handler]
#3  0xb694a94b in KWinInternal::Client::findModal ()
   from /usr/lib/libkdeinit_kwin.so
#4  0xb694a96e in KWinInternal::Client::findModal ()
   from /usr/lib/libkdeinit_kwin.so
#5  0xb694a96e in KWinInternal::Client::findModal ()
   from /usr/lib/libkdeinit_kwin.so
#6  0xb69785a9 in KWinInternal::Workspace::takeActivity ()
   from /usr/lib/libkdeinit_kwin.so
#7  0xb69786fd in KWinInternal::Workspace::requestFocus ()
   from /usr/lib/libkdeinit_kwin.so
#8  0xb69782fe in KWinInternal::Workspace::activateClient ()
   from /usr/lib/libkdeinit_kwin.so
#9  0xb697b86f in KWinInternal::RootInfo::changeActiveWindow ()
   from /usr/lib/libkdeinit_kwin.so
#10 0xb78dece5 in NETRootInfo::event () from /usr/lib/libkdecore.so.4
#11 0xb78deea6 in NETRootInfo::event () from /usr/lib/libkdecore.so.4
#12 0xb695ba18 in KWinInternal::Workspace::netCheck ()
   from /usr/lib/libkdeinit_kwin.so
#13 0xb698bcca in KWinInternal::Workspace::workspaceEvent ()
   from /usr/lib/libkdeinit_kwin.so
#14 0xb698c566 in KWinInternal::Application::x11EventFilter ()
   from /usr/lib/libkdeinit_kwin.so
#15 0xb724c885 in qt_set_x11_event_filter () from /usr/lib/libqt-mt.so.3
#16 0xb7259831 in QApplication::x11ProcessEvent () from /usr/lib/libqt-mt.so.3
#17 0xb727395c in QEventLoop::processEvents () from /usr/lib/libqt-mt.so.3
#18 0xb72e8ea2 in QEventLoop::enterLoop () from /usr/lib/libqt-mt.so.3
#19 0xb72e8dcb in QEventLoop::exec () from /usr/lib/libqt-mt.so.3
#20 0xb72cf305 in QApplication::exec () from /usr/lib/libqt-mt.so.3
#21 0xb698e927 in kdemain () from /usr/lib/libkdeinit_kwin.so
#22 0xb7fde530 in kdeinitmain () from /usr/lib/kde3/kwin.so