Application: plasma-desktop (0.3)
KDE Platform Version: 4.4.85 (KDE 4.4.85 (KDE 4.5 Beta2)) "release 3"
Qt Version: 4.6.3
Operating System: Linux 2.6.31.12-0.2-pae i686
Distribution: "openSUSE 11.2 (i586)"

-- Information about the crash:
Based on a fresh and clean KDE 4.5 Beta 2 setup I activated the PVD (per-virtual-desktop = different widgets on virtual desktops) option. Then I added some plasmoids to the 4 virtual desktops. After that I opened the activity manager and cloned the current activity. During that operation plasma crashes.

So more than one activitiy with enabled PVD option is not a good choice. But like Aaron said, the PVD option is not used by the developers. Maybe it will not be supported in future KDE versions anymore. We'll see.

I will test somemore with the PVD option and the activity stuff.

The crash can be reproduced some of the time.

-- Backtrace:
Application: Plasma-Arbeitsfläche (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0xb5993700 (LWP 2976))]

Thread 2 (Thread 0xab181b70 (LWP 4215)):
#0  0xffffe424 in __kernel_vsyscall ()
#1  0xb6c55d95 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb4002957 in ?? () from /usr/lib/libQtWebKit.so.4
#3  0xb400299f in ?? () from /usr/lib/libQtWebKit.so.4
#4  0xb6c516e5 in start_thread () from /lib/libpthread.so.0
#5  0xb6c51600 in ?? () from /lib/libpthread.so.0

Thread 1 (Thread 0xb5993700 (LWP 2976)):
[KCrash Handler]
#7  0xb5fe5f0e in rewind () from /lib/libc.so.6
#8  0xaa8e914d in KHolidays::HolidayParserDriverPlan::scannerReset (this=0x8855c50) from /usr/lib/libkholidays.so.4
#9  0xaa8ddfdd in KHolidays::HolidayParserDriverPlan::parse (this=0x8855c50) at /usr/src/debug/kdepimlibs-4.4.85/kholidays/parsers/plan2/holidayparserdriverplan.cpp:99
#10 0xaa8dad1f in KHolidays::HolidayParserDriver::parseHolidays (this=0x8855c50, startDate=..., endDate=...) at /usr/src/debug/kdepimlibs-4.4.85/kholidays/parsers/holidayparserdriver.cpp:68
#11 0xaa8d66c0 in KHolidays::HolidayRegion::holidays (this=0x8184ca0, startDate=..., endDate=...) at /usr/src/debug/kdepimlibs-4.4.85/kholidays/holidayregion.cpp:321
#12 0xaa92e50f in CalendarEngine::holidayCalendarSourceRequest (this=0x86b42f0, key=..., args=..., request=...)
    at /usr/src/debug/kdebase-workspace-4.4.85/plasma/generic/dataengines/calendar/calendarengine.cpp:258
#13 0xaa92f9e3 in CalendarEngine::sourceRequestEvent (this=0x86b42f0, request=...) at /usr/src/debug/kdebase-workspace-4.4.85/plasma/generic/dataengines/calendar/calendarengine.cpp:65
#14 0xb4ec645b in Plasma::DataEnginePrivate::requestSource (this=0x86c8ee0, sourceName=..., newSource=0xbfbf843f) at /usr/src/debug/kdelibs-4.4.85/plasma/dataengine.cpp:684
#15 0xb4ec6611 in Plasma::DataEngine::query (this=0x86b42f0, source=...) at /usr/src/debug/kdelibs-4.4.85/plasma/dataengine.cpp:134
#16 0xab30ab1d in Plasma::CalendarTable::populateHolidays (this=0x8c44bf8) at /usr/src/debug/kdebase-workspace-4.4.85/libs/plasmaclock/calendartable.cpp:584
#17 0xab310d46 in Plasma::CalendarTable::setHolidaysRegion (this=0x8c44bf8, region=...) at /usr/src/debug/kdebase-workspace-4.4.85/libs/plasmaclock/calendartable.cpp:500
#18 0xab311372 in Plasma::CalendarTable::applyConfiguration (this=0x8c44bf8, cg=) at /usr/src/debug/kdebase-workspace-4.4.85/libs/plasmaclock/calendartable.cpp:649
#19 0xab306992 in Plasma::Calendar::applyConfiguration (this=0xac72920, cg=<incomplete type>) at /usr/src/debug/kdebase-workspace-4.4.85/libs/plasmaclock/calendar.cpp:288
#20 0xab3020c6 in ClockApplet::configChanged (this=0x9450e70) at /usr/src/debug/kdebase-workspace-4.4.85/libs/plasmaclock/clockapplet.cpp:388
#21 0xab3000f7 in ClockApplet::init (this=0x9450e70) at /usr/src/debug/kdebase-workspace-4.4.85/libs/plasmaclock/clockapplet.cpp:562
#22 0xa7097221 in AdjustableClock::init (this=0x9450e70) at /usr/src/debug/adjustableclock-2.2/applet/AdjustableClock.cpp:75
#23 0xb4ea984f in Plasma::ContainmentPrivate::initApplets (this=0x9821880) at /usr/src/debug/kdelibs-4.4.85/plasma/containment.cpp:474
#24 0xb4ebf71a in Plasma::CoronaPrivate::importLayout (this=0x813de18, conf=..., mergeConfig=true) at /usr/src/debug/kdelibs-4.4.85/plasma/corona.cpp:515
#25 0xb4ec03d9 in Plasma::Corona::importLayout (this=0x813fdb0, conf=...) at /usr/src/debug/kdelibs-4.4.85/plasma/corona.cpp:462
#26 0xb2ee7e54 in Activity::open (this=0xad256c0) at /usr/src/debug/kdebase-workspace-4.4.85/plasma/desktop/shell/activity.cpp:327
#27 0xb2ee81fd in Activity::ensureActive (this=0xad256c0) at /usr/src/debug/kdebase-workspace-4.4.85/plasma/desktop/shell/activity.cpp:177
#28 0xb2ef21d4 in DesktopCorona::activityAdded (this=0x813fdb0, id=...) at /usr/src/debug/kdebase-workspace-4.4.85/plasma/desktop/shell/desktopcorona.cpp:599
#29 0xb2ef2384 in DesktopCorona::activity (this=0x813fdb0, id=...) at /usr/src/debug/kdebase-workspace-4.4.85/plasma/desktop/shell/desktopcorona.cpp:584
#30 0xb2ef23e6 in DesktopCorona::currentActivityChanged (this=0x813fdb0, newActivity=...) at /usr/src/debug/kdebase-workspace-4.4.85/plasma/desktop/shell/desktopcorona.cpp:574
#31 0xb2ef5bfb in DesktopCorona::qt_metacall (this=0x813fdb0, _c=InvokeMetaMethod, _id=58, _a=0xbfbf8e48) at /usr/src/debug/kdebase-workspace-4.4.85/build/plasma/desktop/shell/desktopcorona.moc:122
#32 0xb6dd799d in QMetaObject::metacall (object=0x813fdb0, cl=InvokeMetaMethod, idx=58, argv=0xbfbf8e48) at kernel/qmetaobject.cpp:237
#33 0xb6de6bb0 in QMetaObject::activate (sender=0x81cf980, m=0xb2e8c860, local_signal_index=0, argv=0xbfbf8e48) at kernel/qobject.cpp:3287
#34 0xb2e5ae15 in KActivityConsumer::currentActivityChanged (this=0x81cf980, _t1=...) at /usr/src/debug/kdebase-workspace-4.4.85/build/libs/kworkspace/moc_kactivityconsumer.cpp:126
#35 0xb2e5b2a3 in KActivityConsumer::qt_metacall (this=0x81cf980, _c=InvokeMetaMethod, _id=0, _a=0xbfbf8fd8)
    at /usr/src/debug/kdebase-workspace-4.4.85/build/libs/kworkspace/moc_kactivityconsumer.cpp:87
#36 0xb2e5b582 in KActivityController::qt_metacall (this=0x81cf980, _c=InvokeMetaMethod, _id=4, _a=0xbfbf8fd8)
    at /usr/src/debug/kdebase-workspace-4.4.85/build/libs/kworkspace/moc_kactivitycontroller.cpp:77
#37 0xb6dd799d in QMetaObject::metacall (object=0x81cf980, cl=InvokeMetaMethod, idx=4, argv=0xbfbf8fd8) at kernel/qmetaobject.cpp:237
#38 0xb6de6bb0 in QMetaObject::activate (sender=0x81e1e10, m=0xb2e8cda4, local_signal_index=1, argv=0xbfbf8fd8) at kernel/qobject.cpp:3287
#39 0xb2e7bac5 in OrgKdeActivityManagerInterface::CurrentActivityChanged (this=0x81e1e10, _t1=...) at /usr/src/debug/kdebase-workspace-4.4.85/build/libs/kworkspace/activitymanager_interface.moc:165
#40 0xb2e7bf17 in OrgKdeActivityManagerInterface::qt_metacall (this=0x81e1e10, _c=InvokeMetaMethod, _id=1, _a=0xbfbf92fc)
    at /usr/src/debug/kdebase-workspace-4.4.85/build/libs/kworkspace/activitymanager_interface.moc:112
#41 0xb5e1dd5e in QDBusConnectionPrivate::deliverCall (this=0x809c288, object=0x81e1e10, msg=..., metaTypes=..., slotIdx=179634816) at qdbusintegrator.cpp:904
#42 0xb5e2a2d6 in QDBusCallDeliveryEvent::placeMetaCall (this=0xabbfbb0, object=0x81e1e10) at qdbusintegrator_p.h:101
#43 0xb6de34cf in QObject::event (this=0x81e1e10, e=0xabbfbb0) at kernel/qobject.cpp:1240
#44 0xb63082ac in QApplicationPrivate::notify_helper (this=0x80a2dd0, receiver=0x81e1e10, e=0xabbfbb0) at kernel/qapplication.cpp:4302
#45 0xb630f0e8 in QApplication::notify (this=0x809bbf0, receiver=0x81e1e10, e=0xabbfbb0) at kernel/qapplication.cpp:4185
#46 0xb74dd541 in KApplication::notify (this=0x809bbf0, receiver=0x81e1e10, event=0xabbfbb0) at /usr/src/debug/kdelibs-4.4.85/kdeui/kernel/kapplication.cpp:302
#47 0xb6dd258e in QCoreApplication::notifyInternal (this=0x809bbf0, receiver=0x81e1e10, event=0xabbfbb0) at kernel/qcoreapplication.cpp:726
#48 0xb6dd6097 in sendEvent (event=<value optimized out>, receiver=<value optimized out>) at kernel/qcoreapplication.h:215
#49 QCoreApplicationPrivate::sendPostedEvents (event=<value optimized out>, receiver=<value optimized out>) at kernel/qcoreapplication.cpp:1367
#50 0xb6dd621c in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1260
#51 0xb6dff6cd in sendPostedEvents () at kernel/qcoreapplication.h:220
#52 postEventSourceDispatch () at kernel/qeventdispatcher_glib.cpp:276
#53 0xb5b734f2 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#54 0xb5b76dc8 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#55 0xb5b76eee in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#56 0xb6dff1b1 in QEventDispatcherGlib::processEvents (this=0x809efd8, flags=...) at kernel/qeventdispatcher_glib.cpp:412
#57 0xb63c8dfa in QGuiEventDispatcherGlib::processEvents (this=0x809efd8, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#58 0xb6dd0bfd in QEventLoop::processEvents (this=0xbfbf9ae4, flags=) at kernel/qeventloop.cpp:149
#59 0xb6dd1049 in QEventLoop::exec (this=0xbfbf9ae4, flags=...) at kernel/qeventloop.cpp:201
#60 0xb6dd62f0 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1003
#61 0xb6308354 in QApplication::exec () at kernel/qapplication.cpp:3581
#62 0xb2efca2f in kdemain (argc=1, argv=0x80970d8) at /usr/src/debug/kdebase-workspace-4.4.85/plasma/desktop/shell/main.cpp:118
#63 0x0804ea77 in _start ()

Reported using DrKonqi