Version:            (using KDE 4.2.4)
OS:                Linux
Installed from:    Mandriva RPMs

It may be a coincidence but when Plasma reported the crash I had just opened a slightly different (older) version of /etc/xorg.conf when the current version was open in KWrite. Both versions of KWrite continued to function.

Application: Plasma Workspace (plasma), signal SIGSEGV
[Current thread is 1 (Thread 0xb4bbbae0 (LWP 2067))]

Thread 3 (Thread 0xa94b9b90 (LWP 2068)):
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb51aac45 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i686/libpthread.so.0
#2  0xb7fa78dd in pthread_cond_wait () from /lib/i686/libc.so.6
#3  0xb68213eb in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#4  0xb5258ba4 in ?? () from /usr/lib/libQtNetwork.so.4
#5  0xb68202e3 in ?? () from /usr/lib/libQtCore.so.4
#6  0xb51a7315 in start_thread () from /lib/i686/libpthread.so.0
#7  0xb7f9a25e in clone () from /lib/i686/libc.so.6

Thread 2 (Thread 0xa8c80b90 (LWP 2070)):
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb51aac45 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i686/libpthread.so.0
#2  0xb7fa78dd in pthread_cond_wait () from /lib/i686/libc.so.6
#3  0xb68213eb in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#4  0xa9a703e6 in ?? () from /usr/lib/kde4/plasma_wallpaper_image.so
#5  0xb68202e3 in ?? () from /usr/lib/libQtCore.so.4
#6  0xb51a7315 in start_thread () from /lib/i686/libpthread.so.0
#7  0xb7f9a25e in clone () from /lib/i686/libc.so.6

Thread 1 (Thread 0xb4bbbae0 (LWP 2067)):
[KCrash Handler]
#6  0xa956f152 in TaskManager::GroupManager::add () from /usr/lib/libtaskmanager.so.4
#7  0xa9570c32 in TaskManager::GroupManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#8  0xb69327d5 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#9  0xb69334d5 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#10 0xa9588c65 in TaskManager::TaskManager::taskAdded () from /usr/lib/libtaskmanager.so.4
#11 0xa958af60 in TaskManager::TaskManager::windowAdded () from /usr/lib/libtaskmanager.so.4
#12 0xa958c0cd in TaskManager::TaskManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#13 0xb69327d5 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#14 0xb69334d5 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#15 0xb79bf105 in KWindowSystem::windowAdded () from /usr/lib/libkdeui.so.5
#16 0xb79c1a06 in ?? () from /usr/lib/libkdeui.so.5
#17 0xb79d1bf7 in NETRootInfo::update () from /usr/lib/libkdeui.so.5
#18 0xb79d1f6d in NETRootInfo::event () from /usr/lib/libkdeui.so.5
#19 0xb79c1e49 in ?? () from /usr/lib/libkdeui.so.5
#20 0xb7871003 in KApplication::x11EventFilter () from /usr/lib/libkdeui.so.5
#21 0xb8049964 in ?? () from /usr/lib/libkdeinit4_plasma.so
#22 0xb6c013bf in ?? () from /usr/lib/libQtGui.so.4
#23 0xb6c150ad in QApplication::x11ProcessEvent () from /usr/lib/libQtGui.so.4
#24 0xb6c40ca4 in ?? () from /usr/lib/libQtGui.so.4
#25 0xb4f90cea in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#26 0xb4f94354 in ?? () from /usr/lib/libglib-2.0.so.0
#27 0xb4f944df in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#28 0xb694958a in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#29 0xb6c403fa in ?? () from /usr/lib/libQtGui.so.4
#30 0xb691afa3 in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#31 0xb691b3fd in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#32 0xb691d956 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#33 0xb6b9b4d4 in QApplication::exec () from /usr/lib/libQtGui.so.4
#34 0xb8038a22 in kdemain () from /usr/lib/libkdeinit4_plasma.so
#35 0x0804856f in _start ()