Version:            (using KDE 4.1.1)
Installed from:    Ubuntu Packages

Originally reported here: https://launchpad.net/bugs/269829

The crash the user reports occurs during log-in, and has happened predictably since the second time he has logged in. I will attach a copy of the user's plasma-appletsrc in a minute. Here is the backtrace:

#0  0x00007fe0be171b20 in QGraphicsLinearLayout::orientation () from /usr/lib/libQtGui.so.4
#1  0x00007fe0ae3b5e39 in LockOut::checkLayout (this=0x2705410)
    at /build/buildd/kdebase-workspace-4.1.1/plasma/applets/lock_logout/lockout.cpp:89
	direction = Qt::Vertical
	ratioToKeep = 2
#2  0x00007fe0bfc4c002 in Plasma::Applet::flushPendingConstraintsEvents (this=0x2705410) at /usr/include/qt4/QtCore/qglobal.h:1919
No locals.
#3  0x00007fe0bee84703 in QObject::event () from /usr/lib/libQtCore.so.4
#4  0x00007fe0be174b5b in QGraphicsWidget::event () from /usr/lib/libQtGui.so.4
#5  0x00007fe0bdc195dd in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#6  0x00007fe0bdc2136a in QApplication::notify () from /usr/lib/libQtGui.so.4
#7  0x00007fe0bf7d129b in KApplication::setTopWidget (this=0x7fffc872c450, topWidget=0x2571200)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kdeui/kernel/kapplication.cpp:1152
No locals.
#8  0x00007fffc872c450 in ?? ()
#9  0x0000000002571200 in ?? ()
#10 0x00007fe0bee75a1f in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#11 0x00007fe0beea1726 in ?? () from /usr/lib/libQtCore.so.4
#12 0x00007fe0bee9de6d in ?? () from /usr/lib/libQtCore.so.4
#13 0x00007fe0b964ad62 in IA__g_main_context_dispatch (context=0x257c520) at /build/buildd/glib2.0-2.18.0/glib/gmain.c:2142
No locals.
#14 0x00007fe0b964e4fd in g_main_context_iterate (context=0x257c520, block=1, dispatch=1, self=<value optimized out>)
    at /build/buildd/glib2.0-2.18.0/glib/gmain.c:2775
	max_priority = 0
	timeout = 0
	some_ready = 1
	nfds = 5
	allocated_nfds = <value optimized out>
	fds = (GPollFD *) 0x29cab90
	__PRETTY_FUNCTION__ = "g_main_context_iterate"
#15 0x00007fe0b964e6bb in IA__g_main_context_iteration (context=0x257c520, may_block=1)
    at /build/buildd/glib2.0-2.18.0/glib/gmain.c:2838
	retval = <value optimized out>
#16 0x00007fe0bee9ddcf in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#17 0x00007fe0bdcaae5f in ?? () from /usr/lib/libQtGui.so.4
#18 0x00007fe0bee74342 in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#19 0x00007fe0bee744cd in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#20 0x00007fe0bd3d94ec in KIO::NetAccess::enter_loop (this=0x7fffc872c780)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kio/kio/netaccess.cpp:494
	eventLoop = <incomplete type>
#21 0x00007fe0bd3d96d5 in KIO::NetAccess::statInternal (this=0x7fffc872c780, url=<value optimized out>, 
    details=<value optimized out>, side=KIO::NetAccess::SourceSide, window=0x0)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kio/kio/netaccess.cpp:346
	job = <value optimized out>
#22 0x00007fe0bd3da3ae in KIO::NetAccess::stat (url=@0x7fffc872c980, entry=@0x7fffc872c7f0, window=0x0)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kio/kio/netaccess.cpp:221
	kioNet = {<> = {<No data fields>}, static staticMetaObject = {d = {superdata = 0x7fe0bf152260, 
      stringdata = 0x7fe0bd4c2fa0 "KIO::NetAccess", data = 0x7fe0bd4c30a0, extradata = 0x0}}, d = 0x2a01a90}
	ret = <value optimized out>
#23 0x00007fe0bd3da43c in KIO::NetAccess::mostLocalUrl (url=@0x7fffc872c980, window=0x0)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kio/kio/netaccess.cpp:234
	entry = {d = {d = 0x2a00900}}
	path = {static null = {<No data fields>}, static shared_null = {ref = {_q_value = 5865}, alloc = 0, size = 0, 
    data = 0x7fe0bf15d2da, clean = 0, simpletext = 0, righttoleft = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, 
  static shared_empty = {ref = {_q_value = 117}, alloc = 0, size = 0, data = 0x7fe0bf15d2fa, clean = 0, simpletext = 0, 
    righttoleft = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, d = 0x2a008d0, static codecForCStrings = 0x0}
#24 0x00007fe0ae5c3818 in IconApplet::setUrl (this=0x26e4ac0, url=@0x10)
    at /build/buildd/kdebase-workspace-4.1.1/plasma/applets/icon/icon.cpp:109
No locals.
#25 0x00007fe0ae5c3f6d in IconApplet::init (this=0x26e4ac0) at /build/buildd/kdebase-workspace-4.1.1/plasma/applets/icon/icon.cpp:78
	layout = <value optimized out>
	cg = {<KConfigBase> = {_vptr.KConfigBase = 0x7fe0bf5a5170}, d = {d = 0x29cbe10}}
#26 0x00007fe0bfc791e9 in Plasma::Corona::loadLayout (this=0x26287f0, configName=<value optimized out>)
    at /usr/include/qt4/QtCore/qlist.h:560
	_container_ = {c = {{p = {static shared_null = {ref = {_q_value = 8144}, alloc = 0, begin = 0, end = 0, sharable = 1, 
          array = {0x0}}, d = 0x28844d0}, d = 0x28844d0}}, brk = 0, i = {i = 0x28844e8}, e = {i = 0x2884510}}
	cid = {static null = {<No data fields>}, static shared_null = {ref = {_q_value = 5865}, alloc = 0, size = 0, 
    data = 0x7fe0bf15d2da, clean = 0, simpletext = 0, righttoleft = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, 
  static shared_empty = {ref = {_q_value = 117}, alloc = 0, size = 0, data = 0x7fe0bf15d2fa, clean = 0, simpletext = 0, 
    righttoleft = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, d = 0x25ff820, static codecForCStrings = 0x0}
	containmentConfig = {<KConfigBase> = {_vptr.KConfigBase = 0x7fe0bf5a5170}, d = {d = 0x263d5c0}}
	containment = (class Plasma::Containment *) 0x26fe310
	_container_ = {c = {{p = {static shared_null = {ref = {_q_value = 8144}, alloc = 0, begin = 0, end = 0, sharable = 1, 
          array = {0x0}}, d = 0x2651b20}, d = 0x2651b20}}, brk = 0, i = {i = 0x2651b40}, e = {i = 0x2651b48}}
	c = {d = 0x26290b0}
	containments = {<KConfigBase> = {_vptr.KConfigBase = 0x7fe0bf5a5170}, d = {d = 0x263d4a0}}
#27 0x00007fe0bfc79f12 in Plasma::Corona::setImmutability (this=0x25fc550, immutable=40011760)
    at /usr/include/qt4/QtCore/qbytearray.h:403
	__PRETTY_FUNCTION__ = "void Plasma::Corona::setImmutability(Plasma::ImmutabilityType)"
#28 0x00000000026287f0 in ?? ()
#29 0x0000000002571200 in ?? ()
#30 0x00000000025fc550 in ?? ()
#31 0x00007fffc872cd10 in ?? ()
#32 0x00007fe0c02ff408 in PlasmaApp::corona (this=0x7fffc872cc90)
    at /build/buildd/kdebase-workspace-4.1.1/plasma/plasma/plasmaapp.cpp:404
	c = <value optimized out>
#33 0x00007fe0c0300994 in PlasmaApp (this=0x2571200, display=<value optimized out>, visual=<value optimized out>, 
    colormap=<value optimized out>) at /build/buildd/kdebase-workspace-4.1.1/plasma/plasma/plasmaapp.cpp:228
No locals.
#34 0x00007fe0c03028ff in PlasmaApp::self () at /build/buildd/kdebase-workspace-4.1.1/plasma/plasma/plasmaapp.cpp:114
No locals.
#35 0x00007fe0c02f5f8c in kdemain (argc=1, argv=0x7fffc872d1a8) at /build/buildd/kdebase-workspace-4.1.1/plasma/plasma/main.cpp:55
	aboutData = {d = 0x25463b0}
	options = {d = 0x2554410}
	app = <value optimized out>
	rc = <value optimized out>
#36 0x00007fe0bff86466 in __libc_start_main () from /lib/libc.so.6
#37 0x0000000000400659 in _start ()
No locals.