Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.2 (KDE 4.3.2)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-14-generic i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
I left the PC, with a few browser windows and a terminal open. When I came back, Plasma had crashed.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0xb7823700 (LWP 20309))]

Thread 2 (Thread 0xaa2c8b70 (LWP 20312)):
#0  0x00440422 in __kernel_vsyscall ()
#1  0x00171e15 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0x0051a78d in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0x00686e67 in QWaitConditionPrivate::wait (this=0x98b33d0, mutex=0x98b33cc, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  QWaitCondition::wait (this=0x98b33d0, mutex=0x98b33cc, time=4294967295) at thread/qwaitcondition_unix.cpp:159
#5  0x04a0b922 in QHostInfoAgent::run (this=0x98b33c0) at kernel/qhostinfo.cpp:260
#6  0x00685e32 in QThreadPrivate::start (arg=0x98b33c0) at thread/qthread_unix.cpp:188
#7  0x0016d80e in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#8  0x0050d7ee in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb7823700 (LWP 20309)):
[KCrash Handler]
#6  0x001d6d57 in XVisualIDFromVisual () from /usr/lib/libX11.so.6
#7  0x011d770e in qt_x11_getX11InfoForWindow (xinfo=0xa5fb21c, a=...) at kernel/qwidget_x11.cpp:400
#8  0x011deb4e in QWidgetPrivate::create_sys (this=0xa5fb128, window=30286403, initializeWindow=true, destroyOldWindow=true) at kernel/qwidget_x11.cpp:545
#9  0x0119fb1c in QWidget::create (this=0x9edd758, window=30286403, initializeWindow=true, destroyOldWindow=<value optimized out>) at kernel/qwidget.cpp:1253
#10 0x084b8c1e in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#11 0x084b43f0 in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#12 0x084b44cb in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#13 0x0078c263 in QMetaObject::activate (sender=0x907f920, from_signal_index=4, to_signal_index=4, argv=0x0) at kernel/qobject.cpp:3113
#14 0x0078cec2 in QMetaObject::activate (sender=0x907f920, m=0x866908, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3187
#15 0x00791387 in QSingleShotTimer::timeout (this=0x907f920) at .moc/release-shared/qtimer.moc:76
#16 0x0079149c in QSingleShotTimer::timerEvent (this=0x907f920) at kernel/qtimer.cpp:298
#17 0x007863bf in QObject::event (this=0x907f920, e=0xbf81f830) at kernel/qobject.cpp:1075
#18 0x01148f54 in QApplicationPrivate::notify_helper (this=0x8fc6518, receiver=0x907f920, e=0xbf81f830) at kernel/qapplication.cpp:4056
#19 0x0115067c in QApplication::notify (this=0x8f9f670, receiver=0x907f920, e=0xbf81f830) at kernel/qapplication.cpp:3603
#20 0x050a8bfa in KApplication::notify (this=0x8f9f670, receiver=0x907f920, event=0xbf81f830) at ../../kdeui/kernel/kapplication.cpp:302
#21 0x007766cb in QCoreApplication::notifyInternal (this=0x8f9f670, receiver=0x907f920, event=0xbf81f830) at kernel/qcoreapplication.cpp:610
#22 0x007a37ce in QCoreApplication::sendEvent (this=0x8fc8ccc) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#23 QTimerInfoList::activateTimers (this=0x8fc8ccc) at kernel/qeventdispatcher_unix.cpp:572
#24 0x007a10e0 in timerSourceDispatch (source=0x8fc8c98) at kernel/qeventdispatcher_glib.cpp:165
#25 0x008c9e78 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#26 0x008cd720 in ?? () from /lib/libglib-2.0.so.0
#27 0x008cd853 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#28 0x007a102c in QEventDispatcherGlib::processEvents (this=0x8fc6308, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#29 0x011e9be5 in QGuiEventDispatcherGlib::processEvents (this=0x8fc6308, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#30 0x00774c79 in QEventLoop::processEvents (this=0xbf81faf4, flags=) at kernel/qeventloop.cpp:149
#31 0x007750ca in QEventLoop::exec (this=0xbf81faf4, flags=...) at kernel/qeventloop.cpp:201
#32 0x0077753f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#33 0x01148dd7 in QApplication::exec () at kernel/qapplication.cpp:3525
#34 0x0633d80d in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#35 0x0804dde1 in launch (argc=<value optimized out>, _name=<value optimized out>, args=<value optimized out>, cwd=0x0, envc=0, envs=0x8f88c20 "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x80511a5 "0") at ../../kinit/kinit.cpp:677
#36 0x0804ea35 in handle_launcher_request (sock=<value optimized out>, who=<value optimized out>) at ../../kinit/kinit.cpp:1169
#37 0x0804eeac in handle_requests (waitForPid=<value optimized out>) at ../../kinit/kinit.cpp:1362
#38 0x0804fbaf in main (argc=2, argv=0xbf820354, envp=0xbf820360) at ../../kinit/kinit.cpp:1793

Reported using DrKonqi