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 have only one panel on my desktop.  It contains the K start button, the system tray, clock, weather widget, etc.  I clicked the semicircle on the right of the panel to reveal the "Screen Edge" button, which I clicked and dragged from the bottom of my screen to the left edge of my screen.  That's when Plasma Crashed.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0xb78c2700 (LWP 2171))]

Thread 2 (Thread 0xac7cbb70 (LWP 2174)):
#0  0x008d2422 in __kernel_vsyscall ()
#1  0x00171e15 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0x0358478d in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0x001fae67 in QWaitConditionPrivate::wait (this=0x9951ea0, mutex=0x9951e9c, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  QWaitCondition::wait (this=0x9951ea0, mutex=0x9951e9c, time=4294967295) at thread/qwaitcondition_unix.cpp:159
#5  0x01901922 in QHostInfoAgent::run (this=0x9951e90) at kernel/qhostinfo.cpp:260
#6  0x001f9e32 in QThreadPrivate::start (arg=0x9951e90) at thread/qthread_unix.cpp:188
#7  0x0016d80e in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#8  0x035777ee in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb78c2700 (LWP 2171)):
[KCrash Handler]
#6  Tasks::itemTopMargin (this=0xa080688) at ../../../../plasma/applets/tasks/tasks.h:92
#7  AbstractTaskItem::basicPreferredSize (this=0xa080688) at ../../../../plasma/applets/tasks/abstracttaskitem.cpp:102
#8  0x01f595f9 in TaskItemLayout::maximumRows (this=0x98718b0) at ../../../../plasma/applets/tasks/taskitemlayout.cpp:185
#9  0x01f63004 in TaskGroupItem::optimumCapacity (this=0x9a9eac8) at ../../../../plasma/applets/tasks/taskgroupitem.cpp:1233
#10 0x01f54528 in Tasks::adjustGroupingStrategy (this=0x9898708) at ../../../../plasma/applets/tasks/tasks.cpp:245
#11 0x01f547bc in Tasks::constraintsEvent (this=0x9898708, constraints=) at ../../../../plasma/applets/tasks/tasks.cpp:169
#12 0x01a5f843 in Plasma::Applet::flushPendingConstraintsEvents (this=0x9898708) at ../../plasma/applet.cpp:1173
#13 0x01a5ff78 in Plasma::Applet::timerEvent (this=0x9898708, event=0xbff9bf60) at ../../plasma/applet.cpp:2120
#14 0x002fa3bf in QObject::event (this=0x9898708, e=0xbff9bf60) at kernel/qobject.cpp:1075
#15 0x01662b64 in QGraphicsWidget::event (this=0x9898708, event=0xbff9bf60) at graphicsview/qgraphicswidget.cpp:1340
#16 0x01009f54 in QApplicationPrivate::notify_helper (this=0x94cb0b8, receiver=0x9898708, e=0xbff9bf60) at kernel/qapplication.cpp:4056
#17 0x0101167c in QApplication::notify (this=0x94a4178, receiver=0x9898708, e=0xbff9bf60) at kernel/qapplication.cpp:3603
#18 0x00d29bfa in KApplication::notify (this=0x94a4178, receiver=0x9898708, event=0xbff9bf60) at ../../kdeui/kernel/kapplication.cpp:302
#19 0x002ea6cb in QCoreApplication::notifyInternal (this=0x94a4178, receiver=0x9898708, event=0xbff9bf60) at kernel/qcoreapplication.cpp:610
#20 0x003177ce in QCoreApplication::sendEvent (this=0x94cda84) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#21 QTimerInfoList::activateTimers (this=0x94cda84) at kernel/qeventdispatcher_unix.cpp:572
#22 0x003150e0 in timerSourceDispatch (source=0x94cda50) at kernel/qeventdispatcher_glib.cpp:165
#23 0x055d6e78 in g_main_dispatch (context=0x94cd090) at /build/buildd/glib2.0-2.22.2/glib/gmain.c:1960
#24 IA__g_main_context_dispatch (context=0x94cd090) at /build/buildd/glib2.0-2.22.2/glib/gmain.c:2513
#25 0x055da720 in g_main_context_iterate (context=0x94cd090, block=<value optimized out>, dispatch=1, self=0x94cabc0) at /build/buildd/glib2.0-2.22.2/glib/gmain.c:2591
#26 0x055da853 in IA__g_main_context_iteration (context=0x94cd090, may_block=1) at /build/buildd/glib2.0-2.22.2/glib/gmain.c:2654
#27 0x0031502c in QEventDispatcherGlib::processEvents (this=0x94caea8, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#28 0x010aabe5 in QGuiEventDispatcherGlib::processEvents (this=0x94caea8, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#29 0x002e8c79 in QEventLoop::processEvents (this=0xbff9c224, flags=) at kernel/qeventloop.cpp:149
#30 0x002e90ca in QEventLoop::exec (this=0xbff9c224, flags=...) at kernel/qeventloop.cpp:201
#31 0x002eb53f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#32 0x01009dd7 in QApplication::exec () at kernel/qapplication.cpp:3525
#33 0x01ced80d in kdemain (argc=1, argv=0x9484d08) at ../../../../plasma/shells/desktop/main.cpp:50
#34 0x0804dde1 in launch (argc=<value optimized out>, _name=<value optimized out>, args=<value optimized out>, cwd=0x0, envc=0, envs=0x9471bc0 "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x80511a5 "0") at ../../kinit/kinit.cpp:677
#35 0x0804ea35 in handle_launcher_request (sock=<value optimized out>, who=<value optimized out>) at ../../kinit/kinit.cpp:1169
#36 0x0804eeac in handle_requests (waitForPid=<value optimized out>) at ../../kinit/kinit.cpp:1362
#37 0x0804fbaf in main (argc=2, argv=0xbff9ca84, envp=0xbff9ca90) at ../../kinit/kinit.cpp:1793

Reported using DrKonqi