Version:            (using KDE 4.2.2)
OS:                Linux
Installed from:    Ubuntu Packages

Plasma crashes randomly.

Here is .xsession-errors
--------------8<-------------
KCrash: Application 'plasma' crashing...
kwin: X Error (error: BadPixmap [4], request: X_FreePixmap[54], resource: 0x140a437)
<unknown program name>(5522)/ checkComposite: Plasma has an argb visual 0x92920a0 27262977
<unknown program name>(5522)/ checkComposite: Plasma can use COMPOSITE for effects on 0x92871a0
kwin: X Error (error: BadPixmap [4], request: X_FreePixmap[54], resource: 0x140a438)
kwin: X Error (error: <unknown>[DAMAGE+0], request: XDamageDestroy[DAMAGE+2], resource: 0x140a436)
kwin: X Error (error: BadPixmap [4], request: X_FreePixmap[54], resource: 0x140a439)
QLayout: Attempting to add QLayout "" to QWidget "", which already has a layout
"KConfigIni: In file /usr/share/kubuntu-default-settings/kde4-profile/default/share/config/kickoffrc, line 3: " Invalid entry (missing '=')
plasma(5523) KServiceFactory::findServiceByDesktopPath: "findServiceByDesktopPath: /home/dkorah/.kde/share/apps/RecentDocuments/b43.desktop not found"
plasma(5523) KServiceFactory::findServiceByDesktopPath: "findServiceByDesktopPath: /home/dkorah/.kde/share/apps/RecentDocuments/KDE-Sys-Log-In-Long.ogg.desktop not found"
plasma(5523) KServiceFactory::findServiceByDesktopPath: "findServiceByDesktopPath: /home/dkorah/.kde/share/apps/RecentDocuments/KDE-Sys-Trash-Emptied.ogg.desktop not found"
plasma(5523) Solid::Control::ManagerBasePrivate::loadBackend: Backend loaded:  "HAL-Power"
Object::connect: Attempt to bind non-signal TaskManager::TaskGroup::editRequest()
QCoreApplication::postEvent: Unexpected null receiver
QPainter::begin: Cannot paint on a null pixmap
QCoreApplication::postEvent: Unexpected null receiver
kdeinit4: preparing to launch
QCoreApplication::postEvent: Unexpected null receiver
QCoreApplication::postEvent: Unexpected null receiver
QCoreApplication::postEvent: Unexpected null receiver
---------------------8<---------------

And the back trace:
----------------8<---------------
Application: Plasma Workspace (plasma), signal SIGSEGV
[Current thread is 0 (LWP 4374)]

Thread 4 (Thread 0xa8468b90 (LWP 4378)):
#0  0xb7fb7430 in __kernel_vsyscall ()
#1  0xb50f70e5 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb63062ed in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0xb64f29b2 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#4  0xb7974152 in ?? () from /usr/lib/libQtNetwork.so.4
#5  0xb64f196e in ?? () from /usr/lib/libQtCore.so.4
#6  0xb50f34ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb62f749e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 3 (Thread 0xa7affb90 (LWP 4379)):
#0  0xb7fb7430 in __kernel_vsyscall ()
#1  0xb50f70e5 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb63062ed in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0xb64f29b2 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#4  0xa85f5b9a in ?? () from /usr/lib/kde4/plasma_wallpaper_image.so
#5  0xb64f196e in ?? () from /usr/lib/libQtCore.so.4
#6  0xb50f34ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb62f749e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 2 (Thread 0xa6456b90 (LWP 4380)):
#0  0xb7fb7430 in __kernel_vsyscall ()
#1  0xb50f70e5 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb63062ed in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0xb64f29b2 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#4  0xa85f5b9a in ?? () from /usr/lib/kde4/plasma_wallpaper_image.so
#5  0xb64f196e in ?? () from /usr/lib/libQtCore.so.4
#6  0xb50f34ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb62f749e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb3cdd730 (LWP 4374)):
[KCrash Handler]
#6  0xb65fc951 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#7  0xa87c80d3 in TaskManager::AbstractGroupingStrategy::groupRemoved () from /usr/lib/libtaskmanager.so.4
#8  0xa87c97d1 in TaskManager::AbstractGroupingStrategy::closeGroup () from /usr/lib/libtaskmanager.so.4
#9  0xa87d0597 in ?? () from /usr/lib/libtaskmanager.so.4
#10 0xa87d123b in ?? () from /usr/lib/libtaskmanager.so.4
#11 0xb65fbca8 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#12 0xb65fc932 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#13 0xa87e2a63 in TaskManager::TaskGroup::itemRemoved () from /usr/lib/libtaskmanager.so.4
#14 0xa87e30b0 in TaskManager::TaskGroup::remove () from /usr/lib/libtaskmanager.so.4
#15 0xa87cbf10 in TaskManager::GroupManager::remove () from /usr/lib/libtaskmanager.so.4
#16 0xa87cdc47 in TaskManager::GroupManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#17 0xb65fbca8 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#18 0xb65fc932 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#19 0xa87e6483 in TaskManager::TaskManager::taskRemoved () from /usr/lib/libtaskmanager.so.4
#20 0xa87e7baf in TaskManager::TaskManager::windowRemoved () from /usr/lib/libtaskmanager.so.4
#21 0xa87e9a14 in TaskManager::TaskManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#22 0xb65fbca8 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#23 0xb65fc932 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#24 0xb7835473 in KWindowSystem::windowRemoved () from /usr/lib/libkdeui.so.5
#25 0xb7837cf6 in ?? () from /usr/lib/libkdeui.so.5
#26 0xb7847242 in NETRootInfo::update () from /usr/lib/libkdeui.so.5
#27 0xb78475bf in NETRootInfo::event () from /usr/lib/libkdeui.so.5
#28 0xb7837f8d in ?? () from /usr/lib/libkdeui.so.5
#29 0xb76eac69 in KApplication::x11EventFilter () from /usr/lib/libkdeui.so.5
#30 0xb7f744d7 in ?? () from /usr/lib/libkdeinit4_plasma.so
#31 0xb68f5fce in ?? () from /usr/lib/libQtGui.so.4
#32 0xb6908738 in QApplication::x11ProcessEvent () from /usr/lib/libQtGui.so.4
#33 0xb6934cfa in ?? () from /usr/lib/libQtGui.so.4
#34 0xb4ef1b88 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#35 0xb4ef50eb in ?? () from /usr/lib/libglib-2.0.so.0
#36 0xb4ef5268 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#37 0xb6611438 in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#38 0xb69343f5 in ?? () from /usr/lib/libQtGui.so.4
#39 0xb65e406a in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#40 0xb65e44aa in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#41 0xb65e6959 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#42 0xb6892da7 in QApplication::exec () from /usr/lib/libQtGui.so.4
#43 0xb7f61b56 in kdemain () from /usr/lib/libkdeinit4_plasma.so
#44 0x08048712 in _start ()