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 2.6.31-15-generic i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
I do not know why, but it crashed and my menu was invisible, but came back after a minute.

 -- Backtrace:
Application: Plasma-Arbeitsfläche (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0xb5815700 (LWP 2147))]

Thread 2 (Thread 0xa79eab70 (LWP 2149)):
#0  0xb7845422 in __kernel_vsyscall ()
#1  0xb5f6fe15 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb613378d in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0xb7648e67 in QWaitConditionPrivate::wait (this=0x8e4a850, mutex=0x8e4a84c, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  QWaitCondition::wait (this=0x8e4a850, mutex=0x8e4a84c, time=4294967295) at thread/qwaitcondition_unix.cpp:159
#5  0xb5e81922 in QHostInfoAgent::run (this=0x8e4a840) at kernel/qhostinfo.cpp:260
#6  0xb7647e32 in QThreadPrivate::start (arg=0x8e4a840) at thread/qthread_unix.cpp:188
#7  0xb5f6b80e in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#8  0xb61267ee in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb5815700 (LWP 2147)):
[KCrash Handler]
#6  0xb726cd57 in XVisualIDFromVisual () from /usr/lib/libX11.so.6
#7  0xb644070e in qt_x11_getX11InfoForWindow (xinfo=0x955a77c, a=...) at kernel/qwidget_x11.cpp:400
#8  0xb6447b4e in QWidgetPrivate::create_sys (this=0x955a688, window=16906983, initializeWindow=true, destroyOldWindow=true) at kernel/qwidget_x11.cpp:545
#9  0xb6408b1c in QWidget::create (this=0x9459e60, window=16906983, initializeWindow=true, destroyOldWindow=<value optimized out>) at kernel/qwidget.cpp:1253
#10 0xa7c81c1e in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#11 0xa7c7d3f0 in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#12 0xa7c7d4cb in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#13 0xb774e263 in QMetaObject::activate (sender=0x966b870, from_signal_index=4, to_signal_index=4, argv=0x0) at kernel/qobject.cpp:3113
#14 0xb774eec2 in QMetaObject::activate (sender=0x966b870, m=0xb7828908, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3187
#15 0xb7753387 in QSingleShotTimer::timeout (this=0x966b870) at .moc/release-shared/qtimer.moc:76
#16 0xb775349c in QSingleShotTimer::timerEvent (this=0x966b870) at kernel/qtimer.cpp:298
#17 0xb77483bf in QObject::event (this=0x966b870, e=0xbfa2d2f0) at kernel/qobject.cpp:1075
#18 0xb63b1f54 in QApplicationPrivate::notify_helper (this=0x85dccc8, receiver=0x966b870, e=0xbfa2d2f0) at kernel/qapplication.cpp:4056
#19 0xb63b967c in QApplication::notify (this=0x85b5cf8, receiver=0x966b870, e=0xbfa2d2f0) at kernel/qapplication.cpp:3603
#20 0xb6e01bfa in KApplication::notify (this=0x85b5cf8, receiver=0x966b870, event=0xbfa2d2f0) at ../../kdeui/kernel/kapplication.cpp:302
#21 0xb77386cb in QCoreApplication::notifyInternal (this=0x85b5cf8, receiver=0x966b870, event=0xbfa2d2f0) at kernel/qcoreapplication.cpp:610
#22 0xb77657ce in QCoreApplication::sendEvent (this=0x85dfa74) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#23 QTimerInfoList::activateTimers (this=0x85dfa74) at kernel/qeventdispatcher_unix.cpp:572
#24 0xb77630e0 in timerSourceDispatch (source=0x85dfa40) at kernel/qeventdispatcher_glib.cpp:165
#25 0xb5fb7e78 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#26 0xb5fbb720 in ?? () from /lib/libglib-2.0.so.0
#27 0xb5fbb853 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#28 0xb776302c in QEventDispatcherGlib::processEvents (this=0x85dc798, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#29 0xb6452be5 in QGuiEventDispatcherGlib::processEvents (this=0x85dc798, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#30 0xb7736c79 in QEventLoop::processEvents (this=0xbfa2d5b4, flags=) at kernel/qeventloop.cpp:149
#31 0xb77370ca in QEventLoop::exec (this=0xbfa2d5b4, flags=...) at kernel/qeventloop.cpp:201
#32 0xb773953f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#33 0xb63b1dd7 in QApplication::exec () at kernel/qapplication.cpp:3525
#34 0xb33f180d 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=0x856b730 "", 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=0xbfa2de14, envp=0xbfa2de20) at ../../kinit/kinit.cpp:1793

Reported using DrKonqi