Version:           4.1.81 (using Devel)
Compiler:          gcc version 4.3.2 (Debian 4.3.2-1) 
OS:                Linux
Installed from:    Compiled sources

This is very simple to reproduce, just install and run "basket". I am using basket version 1.0.2 (using kdelibs 3.5.10) and kde version 4.1.81 (svn 891616).

Backtrace:
Εφαρμογή: Χώρος εργασίας Plasma (plasma), σήμα SIGSEGV
0x00007f464499fff1 in nanosleep () from /lib/libc.so.6
[Current thread is 0 (LWP 7064)]

Thread 3 (Thread 0x41433950 (LWP 7067)):
#0  0x00007f463d6a0d29 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007f4641c94159 in QWaitCondition::wait (this=0xcbb2b0, mutex=0xcbb2a8, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:82
#2  0x00007f463f2a3f4c in QHostInfoAgent::run (this=0xcbb290) at kernel/qhostinfo.cpp:241
#3  0x00007f4641c93162 in QThreadPrivate::start (arg=0xcbb290) at thread/qthread_unix.cpp:185
#4  0x00007f463d69cfc7 in start_thread () from /lib/libpthread.so.0
#5  0x00007f46449d15ad in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x41c34950 (LWP 7068)):
#0  0x00007f463d6a0d29 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007f4641c94159 in QWaitCondition::wait (this=0xba0390, mutex=0xba0388, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:82
#2  0x00007f4628554e10 in RenderThread::run (this=0xba0378) at ../../../../plasma/wallpapers/image/renderthread.cpp:90
#3  0x00007f4641c93162 in QThreadPrivate::start (arg=0xba0378) at thread/qthread_unix.cpp:185
#4  0x00007f463d69cfc7 in start_thread () from /lib/libpthread.so.0
#5  0x00007f46449d15ad in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f4644faa700 (LWP 7064)):
[KCrash Handler]
#5  AbstractTaskItem::basicPreferredSize (this=0x11e84d0) at ../../../../plasma/applets/tasks/tasks.h:92
#6  0x00007f46298acac2 in LayoutWidget::maximumRows (this=0xc8ce10) at ../../../../plasma/applets/tasks/layoutwidget.cpp:197
#7  0x00007f46298b3c1d in TaskGroupItem::optimumCapacity (this=0xce3850) at ../../../../plasma/applets/tasks/taskgroupitem.cpp:838
#8  0x00007f46298a5ce0 in Tasks::adjustGroupingStrategy (this=0xa6f510) at ../../../../plasma/applets/tasks/tasks.cpp:365
#9  0x00007f46298a5f00 in Tasks::constraintsEvent (this=0xa6f510, constraints={i = 1151465104}) at ../../../../plasma/applets/tasks/tasks.cpp:292
#10 0x00007f46445b931f in Plasma::Applet::flushPendingConstraintsEvents (this=0xa6f510) at ../../plasma/applet.cpp:963
#11 0x00007f46445b9ae5 in Plasma::Applet::timerEvent (this=0xa6f510, event=<value optimized out>) at ../../plasma/applet.cpp:1681
#12 0x00007f4641d89fe3 in QObject::event (this=0xa6f510, e=0x7f4644a1f690) at kernel/qobject.cpp:1120
#13 0x00007f46429f6c6b in QGraphicsWidget::event (this=0xa6f510, event=0x7fff4d0eb4f0) at graphicsview/qgraphicswidget.cpp:1239
#14 0x00007f464249ca5d in QApplicationPrivate::notify_helper (this=0x649b10, receiver=0xa6f510, e=0x7fff4d0eb4f0) at kernel/qapplication.cpp:3803
#15 0x00007f46424a47da in QApplication::notify (this=0x630720, receiver=0xa6f510, e=0x7fff4d0eb4f0) at kernel/qapplication.cpp:3768
#16 0x00007f46434c780b in KApplication::notify (this=0x630720, receiver=0xa6f510, event=0x7fff4d0eb4f0) at ../../kdeui/kernel/kapplication.cpp:307
#17 0x00007f4641d7b381 in QCoreApplication::notifyInternal (this=0x630720, receiver=0xa6f510, event=0x7fff4d0eb4f0) at kernel/qcoreapplication.cpp:587
#18 0x00007f4641da7256 in QTimerInfoList::activateTimers (this=0x64d120) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:209
#19 0x00007f4641da37ad in timerSourceDispatch (source=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:160
#20 0x00007f463d8eb78b in IA__g_main_context_dispatch (context=0x64ba20) at /build/buildd/glib2.0-2.16.6/glib/gmain.c:2012
#21 0x00007f463d8eef5d in g_main_context_iterate (context=0x64ba20, block=1, dispatch=1, self=<value optimized out>) at /build/buildd/glib2.0-2.16.6/glib/gmain.c:2645
#22 0x00007f463d8ef11b in IA__g_main_context_iteration (context=0x64ba20, may_block=1) at /build/buildd/glib2.0-2.16.6/glib/gmain.c:2708
#23 0x00007f4641da370f in QEventDispatcherGlib::processEvents (this=0x649570, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:319
#24 0x00007f464252e44f in QGuiEventDispatcherGlib::processEvents (this=0x0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:198
#25 0x00007f4641d79ca2 in QEventLoop::processEvents (this=<value optimized out>, flags={i = 1292810080}) at kernel/qeventloop.cpp:143
#26 0x00007f4641d79e2d in QEventLoop::exec (this=0x7fff4d0eb7a0, flags={i = 1292810160}) at kernel/qeventloop.cpp:194
#27 0x00007f4641d7c2dd in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845
#28 0x00007f4644c8e0e3 in kdemain (argc=1, argv=0x7fff4d0ebb18) at ../../../../plasma/shells/desktop/main.cpp:58
#29 0x00007f46449201a6 in __libc_start_main () from /lib/libc.so.6
#30 0x0000000000400629 in _start ()