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 2.6.31-16-generic i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
I removed my old panel and created a new one. I started draging widgets to the panel. Sometimes they wouldn't stick so I had to drag several of them twice to add them. When I was adding one, don't remember which one, plasma crashed. 

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0xb76df700 (LWP 20602))]

Thread 2 (Thread 0xac5efb70 (LWP 20606)):
#0  0x00c96422 in __kernel_vsyscall ()
#1  0x00602e15 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0x00d7087d in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0x00406e67 in QWaitConditionPrivate::wait (this=0x9f838f8, mutex=0x9f838f4, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  QWaitCondition::wait (this=0x9f838f8, mutex=0x9f838f4, time=4294967295) at thread/qwaitcondition_unix.cpp:159
#5  0x0931e922 in QHostInfoAgent::run (this=0x9f838e8) at kernel/qhostinfo.cpp:260
#6  0x00405e32 in QThreadPrivate::start (arg=0x9f838e8) at thread/qthread_unix.cpp:188
#7  0x005fe80e in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#8  0x00d638de in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb76df700 (LWP 20602)):
[KCrash Handler]
#6  0x00000000 in ?? ()
#7  0x07f1a3ca in Plasma::ToolTipManagerPrivate::showToolTip (this=0x0) at ../../plasma/tooltipmanager.cpp:342
#8  0x07f1a650 in Plasma::ToolTipManager::qt_metacall (this=0x9c09e10, _c=QMetaObject::InvokeMetaMethod, _id=4, _a=0xbfd8fabc) at ./tooltipmanager.moc:69
#9  0x0050c263 in QMetaObject::activate (sender=0x9c0e598, from_signal_index=4, to_signal_index=4, argv=0x0) at kernel/qobject.cpp:3113
#10 0x0050cec2 in QMetaObject::activate (sender=0x9c0e598, m=0x5e7904, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3187
#11 0x00546667 in QTimer::timeout (this=0x9c0e598) at .moc/release-shared/moc_qtimer.cpp:128
#12 0x005119ae in QTimer::timerEvent (this=0x9c0e598, e=0xbfd8ff50) at kernel/qtimer.cpp:261
#13 0x005063bf in QObject::event (this=0x9c0e598, e=0xbfd8ff50) at kernel/qobject.cpp:1075
#14 0x0895df54 in QApplicationPrivate::notify_helper (this=0x9af8e90, receiver=0x9c0e598, e=0xbfd8ff50) at kernel/qapplication.cpp:4056
#15 0x0896567c in QApplication::notify (this=0x9ad1fe8, receiver=0x9c0e598, e=0xbfd8ff50) at kernel/qapplication.cpp:3603
#16 0x0102abfa in KApplication::notify (this=0x9ad1fe8, receiver=0x9c0e598, event=0xbfd8ff50) at ../../kdeui/kernel/kapplication.cpp:302
#17 0x004f66cb in QCoreApplication::notifyInternal (this=0x9ad1fe8, receiver=0x9c0e598, event=0xbfd8ff50) at kernel/qcoreapplication.cpp:610
#18 0x005237ce in QCoreApplication::sendEvent (this=0x9afba74) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#19 QTimerInfoList::activateTimers (this=0x9afba74) at kernel/qeventdispatcher_unix.cpp:572
#20 0x005210e0 in timerSourceDispatch (source=0x9afba40) at kernel/qeventdispatcher_glib.cpp:165
#21 0x008c6e88 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#22 0x008ca730 in ?? () from /lib/libglib-2.0.so.0
#23 0x008ca863 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#24 0x0052102c in QEventDispatcherGlib::processEvents (this=0x9af8c50, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#25 0x089febe5 in QGuiEventDispatcherGlib::processEvents (this=0x9af8c50, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#26 0x004f4c79 in QEventLoop::processEvents (this=0xbfd90214, flags=) at kernel/qeventloop.cpp:149
#27 0x004f50ca in QEventLoop::exec (this=0xbfd90214, flags=...) at kernel/qeventloop.cpp:201
#28 0x004f753f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#29 0x0895ddd7 in QApplication::exec () at kernel/qapplication.cpp:3525
#30 0x0133680d in kdemain (argc=1, argv=0x9a761e8) at ../../../../plasma/shells/desktop/main.cpp:50
#31 0x0804dde1 in launch (argc=<value optimized out>, _name=<value optimized out>, args=<value optimized out>, cwd=0x0, envc=0, envs=0x9a951b0 "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x80511a5 "0") at ../../kinit/kinit.cpp:677
#32 0x0804ea35 in handle_launcher_request (sock=<value optimized out>, who=<value optimized out>) at ../../kinit/kinit.cpp:1169
#33 0x0804eeac in handle_requests (waitForPid=<value optimized out>) at ../../kinit/kinit.cpp:1362
#34 0x0804fbaf in main (argc=2, argv=0xbfd90a74, envp=0xbfd90a80) at ../../kinit/kinit.cpp:1793

Reported using DrKonqi